From 405947fa098a46496c12327e451a6560f2128a88 Mon Sep 17 00:00:00 2001
From: javier <javier@formatinternet.com>
Date: Thu, 29 Jan 2026 19:28:40 +0100
Subject: [PATCH] Update cookbook recipes to use TICK syntax for date filtering
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Replace legacy dateadd(), today(), yesterday(), now() patterns with
the new TICK syntax across 27 cookbook recipes:

- timestamp IN today() → timestamp IN '$today'
- timestamp IN yesterday() → timestamp IN '$yesterday'
- timestamp > dateadd('d', -1, now()) → timestamp IN '$now - 1d..$now'
- @lookback := dateadd(...) → @lookback := '$now - Xd..$now'

Also simplifies VWAP query to use direct window function division.

Adds new elapsed-time recipe in time-series patterns.
---
 documentation/cookbook/demo-data-schema.md    |  6 +-
 .../integrations/grafana/variable-dropdown.md |  2 +-
 .../sql/advanced/conditional-aggregates.md    |  2 +-
 .../advanced/consistent-histogram-buckets.md  | 10 ++--
 .../cookbook/sql/advanced/local-min-max.md    |  4 +-
 .../sql/advanced/pivot-with-others.md         |  4 +-
 .../advanced/rows-before-after-value-match.md |  2 +-
 .../cookbook/sql/advanced/sankey-funnel.md    |  2 +-
 .../sql/advanced/top-n-plus-others.md         |  6 +-
 .../cookbook/sql/advanced/unpivot-table.md    |  4 +-
 .../sql/finance/aggressor-volume-imbalance.md |  2 +-
 .../cookbook/sql/finance/bollinger-bands.md   |  4 +-
 .../sql/finance/bollinger-bandwidth.md        | 10 ++--
 .../sql/finance/liquidity-comparison.md       |  6 +-
 documentation/cookbook/sql/finance/ohlc.md    |  2 +-
 .../cookbook/sql/finance/rolling-stddev.md    |  2 +-
 .../cookbook/sql/finance/tick-trin.md         |  6 +-
 .../cookbook/sql/finance/volume-profile.md    |  4 +-
 .../cookbook/sql/finance/volume-spike.md      |  5 +-
 documentation/cookbook/sql/finance/vwap.md    | 51 ++++++++---------
 .../cookbook/sql/time-series/elapsed-time.md  | 56 +++++++++++++++++++
 .../sql/time-series/fill-from-one-column.md   |  8 +--
 .../time-series/force-designated-timestamp.md |  8 +--
 .../sql/time-series/latest-n-per-partition.md | 18 +++---
 .../sql/time-series/remove-outliers.md        |  6 +-
 .../time-series/sample-by-interval-bounds.md  |  2 +-
 .../sql/time-series/session-windows.md        |  4 +-
 27 files changed, 142 insertions(+), 94 deletions(-)
 create mode 100644 documentation/cookbook/sql/time-series/elapsed-time.md

diff --git a/documentation/cookbook/demo-data-schema.md b/documentation/cookbook/demo-data-schema.md
index 5cb5d1dc3..f46159aec 100644
--- a/documentation/cookbook/demo-data-schema.md
+++ b/documentation/cookbook/demo-data-schema.md
@@ -62,7 +62,7 @@ The table tracks **30 currency pairs**: EURUSD, GBPUSD, USDJPY, USDCHF, AUDUSD,
 
 ```questdb-sql demo title="Recent core_price updates"
 SELECT * FROM core_price
-WHERE timestamp IN today()
+WHERE timestamp IN '$today'
 LIMIT -10;
 ```
 
@@ -116,7 +116,7 @@ SELECT timestamp, symbol,
        array_count(bids[1]) as bid_levels,
        array_count(asks[1]) as ask_levels
 FROM market_data
-WHERE timestamp IN today()
+WHERE timestamp IN '$today'
 LIMIT -5;
 ```
 
@@ -170,7 +170,7 @@ CREATE TABLE 'fx_trades' (
 
 ```questdb-sql demo title="Recent FX trades"
 SELECT * FROM fx_trades
-WHERE timestamp IN today()
+WHERE timestamp IN '$today'
 LIMIT -10;
 ```
 
diff --git a/documentation/cookbook/integrations/grafana/variable-dropdown.md b/documentation/cookbook/integrations/grafana/variable-dropdown.md
index 337caaccb..13897f3f9 100644
--- a/documentation/cookbook/integrations/grafana/variable-dropdown.md
+++ b/documentation/cookbook/integrations/grafana/variable-dropdown.md
@@ -193,7 +193,7 @@ The PostgreSQL data source recognizes `__text` and `__value` as special column n
 **Different filter conditions:**
 ```sql
 -- Filter by time range
-WHERE timestamp IN yesterday()
+WHERE timestamp IN '$yesterday'
 
 -- Filter by multiple criteria
 WHERE symbol LIKE '%USDT' AND price > 1000
diff --git a/documentation/cookbook/sql/advanced/conditional-aggregates.md b/documentation/cookbook/sql/advanced/conditional-aggregates.md
index c59472f81..d4ea0ebe1 100644
--- a/documentation/cookbook/sql/advanced/conditional-aggregates.md
+++ b/documentation/cookbook/sql/advanced/conditional-aggregates.md
@@ -33,7 +33,7 @@ SELECT
   sum(CASE WHEN amount <= 1.0 THEN amount END) as small_trade_volume,
   sum(amount) as total_volume
 FROM trades
-WHERE timestamp >= dateadd('d', -1, now())
+WHERE timestamp IN '$now - 1d..$now'
   AND symbol IN ('BTC-USDT', 'ETH-USDT')
 GROUP BY symbol;
 ```
diff --git a/documentation/cookbook/sql/advanced/consistent-histogram-buckets.md b/documentation/cookbook/sql/advanced/consistent-histogram-buckets.md
index 5734868f4..02e551ca6 100644
--- a/documentation/cookbook/sql/advanced/consistent-histogram-buckets.md
+++ b/documentation/cookbook/sql/advanced/consistent-histogram-buckets.md
@@ -20,7 +20,7 @@ SELECT
   floor(amount / @bucket_size) * @bucket_size AS bucket,
   count(*) AS count
 FROM trades
-WHERE symbol = 'BTC-USDT' AND timestamp IN today()
+WHERE symbol = 'BTC-USDT' AND timestamp IN '$today'
 GROUP BY bucket
 ORDER BY bucket;
 ```
@@ -53,7 +53,7 @@ DECLARE @bucket_count := 50
 
 WITH raw_data AS (
   SELECT price, amount FROM trades
-  WHERE symbol = 'BTC-USDT' AND timestamp IN today()
+  WHERE symbol = 'BTC-USDT' AND timestamp IN '$today'
 ),
 bucket_size AS (
   SELECT (max(price) - min(price)) / (@bucket_count - 1) AS bucket_size FROM raw_data
@@ -83,7 +83,7 @@ SELECT
 FROM trades
 WHERE symbol = 'BTC-USDT'
   AND amount > 0.000001 -- optional. Just adding here for easier visualization
-  AND timestamp IN today()
+  AND timestamp IN '$today'
 GROUP BY bucket
 ORDER BY bucket;
 ```
@@ -104,7 +104,7 @@ SELECT
   END AS bucket,
   count(*) AS count
 FROM trades
-WHERE symbol = 'BTC-USDT' AND timestamp IN today()
+WHERE symbol = 'BTC-USDT' AND timestamp IN '$today'
 GROUP BY bucket;
 ```
 
@@ -119,7 +119,7 @@ SELECT
   floor(amount / @bucket_size) * @bucket_size AS bucket,
   count(*) AS count
 FROM trades
-WHERE symbol = 'BTC-USDT' AND timestamp IN today()
+WHERE symbol = 'BTC-USDT' AND timestamp IN '$today'
 SAMPLE BY 1h
 ORDER BY timestamp, bucket;
 ```
diff --git a/documentation/cookbook/sql/advanced/local-min-max.md b/documentation/cookbook/sql/advanced/local-min-max.md
index 47e731648..eaf2d365e 100644
--- a/documentation/cookbook/sql/advanced/local-min-max.md
+++ b/documentation/cookbook/sql/advanced/local-min-max.md
@@ -19,7 +19,7 @@ SELECT timestamp, bid_price,
   min(bid_price) OVER (ORDER BY timestamp RANGE 1 second PRECEDING) AS min_price,
   max(bid_price) OVER (ORDER BY timestamp RANGE 1 second PRECEDING) AS max_price
 FROM core_price
-WHERE timestamp >= dateadd('m', -1, now()) AND symbol = 'EURUSD';
+WHERE timestamp IN '$now - 1m..$now' AND symbol = 'EURUSD';
 ```
 
 This returns the minimum and maximum bid price from the 1 second preceding each row.
@@ -35,7 +35,7 @@ SELECT p.timestamp, p.bid_price,
 FROM core_price p
 WINDOW JOIN core_price pp ON symbol
   RANGE BETWEEN 1 second PRECEDING AND 1 second FOLLOWING
-WHERE p.timestamp >= dateadd('m', -1, now()) AND p.symbol = 'EURUSD';
+WHERE p.timestamp IN '$now - 1m..$now' AND p.symbol = 'EURUSD';
 ```
 
 This returns the minimum and maximum bid price from 1 second before to 1 second after each row.
diff --git a/documentation/cookbook/sql/advanced/pivot-with-others.md b/documentation/cookbook/sql/advanced/pivot-with-others.md
index 7d3b99f88..13de855c0 100644
--- a/documentation/cookbook/sql/advanced/pivot-with-others.md
+++ b/documentation/cookbook/sql/advanced/pivot-with-others.md
@@ -13,7 +13,7 @@ You want to pivot data so that specific symbols (like EURUSD, GBPUSD, USDJPY) be
 ```questdb-sql demo title="Aggregated data per symbol"
 SELECT timestamp, symbol, SUM(bid_volume) AS total_bid
 FROM core_price
-WHERE timestamp IN today()
+WHERE timestamp IN '$today'
 SAMPLE BY 1m
 LIMIT 20;
 ```
@@ -55,7 +55,7 @@ SELECT timestamp,
   SUM(CASE WHEN symbol NOT IN ('EURUSD', 'GBPUSD', 'USDJPY')
     THEN bid_volume END) AS OTHERS
 FROM core_price
-WHERE timestamp IN today()
+WHERE timestamp IN '$today'
 SAMPLE BY 1m
 LIMIT 5;
 ```
diff --git a/documentation/cookbook/sql/advanced/rows-before-after-value-match.md b/documentation/cookbook/sql/advanced/rows-before-after-value-match.md
index bf36be392..e32862699 100644
--- a/documentation/cookbook/sql/advanced/rows-before-after-value-match.md
+++ b/documentation/cookbook/sql/advanced/rows-before-after-value-match.md
@@ -27,7 +27,7 @@ SELECT timestamp, bid_price,
   LEAD(bid_price, 4) OVER () AS next_4,
   LEAD(bid_price, 5) OVER () AS next_5
 FROM core_price
-WHERE timestamp >= dateadd('m', -1, now()) AND symbol = 'EURUSD';
+WHERE timestamp IN '$now - 1m..$now' AND symbol = 'EURUSD';
 ```
 
 ## How it works
diff --git a/documentation/cookbook/sql/advanced/sankey-funnel.md b/documentation/cookbook/sql/advanced/sankey-funnel.md
index c2bfa908a..98aa042f9 100644
--- a/documentation/cookbook/sql/advanced/sankey-funnel.md
+++ b/documentation/cookbook/sql/advanced/sankey-funnel.md
@@ -43,7 +43,7 @@ WITH PrevEvents AS (
     timestamp,
     lag(timestamp) OVER (PARTITION BY visitor_id ORDER BY timestamp) AS prev_ts
   FROM
-    events WHERE timestamp > dateadd('d', -7, now())
+    events WHERE timestamp IN '$now - 7d..$now'
     AND metric_name = 'page_view'
 ), VisitorSessions AS (
   SELECT *,
diff --git a/documentation/cookbook/sql/advanced/top-n-plus-others.md b/documentation/cookbook/sql/advanced/top-n-plus-others.md
index 9ac7b0aeb..1f602f614 100644
--- a/documentation/cookbook/sql/advanced/top-n-plus-others.md
+++ b/documentation/cookbook/sql/advanced/top-n-plus-others.md
@@ -31,7 +31,7 @@ WITH totals AS (
     symbol,
     count() as total
   FROM trades
-  WHERE timestamp >= dateadd('d', -1, now())
+  WHERE timestamp IN '$now - 1d..$now'
 ),
 ranked AS (
   SELECT
@@ -160,7 +160,7 @@ Results in three groups: top 5 individual, ranks 6-10 combined, rest combined.
 WITH totals AS (
   SELECT symbol, count() as total
   FROM trades
-  WHERE timestamp >= dateadd('d', -1, now())
+  WHERE timestamp IN '$now - 1d..$now'
 ),
 ranked AS (
   SELECT *, rank() OVER (ORDER BY total DESC) as ranking
@@ -196,7 +196,7 @@ WITH totals AS (
     side,
     count() as total
   FROM trades
-  WHERE timestamp >= dateadd('d', -1, now())
+  WHERE timestamp IN '$now - 1d..$now'
 ),
 ranked AS (
   SELECT
diff --git a/documentation/cookbook/sql/advanced/unpivot-table.md b/documentation/cookbook/sql/advanced/unpivot-table.md
index d047a3ffa..8415a9692 100644
--- a/documentation/cookbook/sql/advanced/unpivot-table.md
+++ b/documentation/cookbook/sql/advanced/unpivot-table.md
@@ -42,7 +42,7 @@ WITH pivoted AS (
     CASE WHEN side = 'buy' THEN price END as buy,
     CASE WHEN side = 'sell' THEN price END as sell
   FROM trades
-  WHERE timestamp >= dateadd('m', -5, now())
+  WHERE timestamp IN '$now - 5m..$now'
     AND symbol = 'ETH-USDT'
 ),
 unpivoted AS (
@@ -114,7 +114,7 @@ WITH sensor_data AS (
     humidity,
     pressure
   FROM sensors
-  WHERE timestamp >= dateadd('h', -1, now())
+  WHERE timestamp IN '$now - 1h..$now'
 )
 SELECT timestamp, sensor_id, 'temperature' as metric, temperature as value FROM sensor_data
 WHERE temperature IS NOT NULL
diff --git a/documentation/cookbook/sql/finance/aggressor-volume-imbalance.md b/documentation/cookbook/sql/finance/aggressor-volume-imbalance.md
index 05cd8fd7f..12176502a 100644
--- a/documentation/cookbook/sql/finance/aggressor-volume-imbalance.md
+++ b/documentation/cookbook/sql/finance/aggressor-volume-imbalance.md
@@ -19,7 +19,7 @@ WITH volumes AS (
     SUM(CASE WHEN side = 'buy' THEN amount ELSE 0 END) AS buy_volume,
     SUM(CASE WHEN side = 'sell' THEN amount ELSE 0 END) AS sell_volume
   FROM trades
-  WHERE timestamp IN yesterday()
+  WHERE timestamp IN '$yesterday'
     AND symbol IN ('ETH-USDT', 'BTC-USDT', 'ETH-BTC')
 )
 SELECT
diff --git a/documentation/cookbook/sql/finance/bollinger-bands.md b/documentation/cookbook/sql/finance/bollinger-bands.md
index 76c1ceff0..a9198748d 100644
--- a/documentation/cookbook/sql/finance/bollinger-bands.md
+++ b/documentation/cookbook/sql/finance/bollinger-bands.md
@@ -30,7 +30,7 @@ WITH OHLC AS (
       last(price) AS close,
       sum(quantity) AS volume
  FROM fx_trades
- WHERE symbol = 'EURUSD' AND timestamp IN yesterday()
+ WHERE symbol = 'EURUSD' AND timestamp IN '$yesterday'
  SAMPLE BY 15m
 ), stats AS (
   SELECT
@@ -109,7 +109,7 @@ WITH OHLC AS (
       sum(quantity) AS volume
  FROM fx_trades
  WHERE symbol IN ('EURUSD', 'GBPUSD')
-   AND timestamp IN yesterday()
+   AND timestamp IN '$yesterday'
  SAMPLE BY 15m
 ), stats AS (
   SELECT
diff --git a/documentation/cookbook/sql/finance/bollinger-bandwidth.md b/documentation/cookbook/sql/finance/bollinger-bandwidth.md
index eb7e96e71..2dacba97d 100644
--- a/documentation/cookbook/sql/finance/bollinger-bandwidth.md
+++ b/documentation/cookbook/sql/finance/bollinger-bandwidth.md
@@ -25,8 +25,8 @@ When BandWidth drops to historically low levels, the bands are in a "squeeze". P
 ```questdb-sql demo title="Calculate Bollinger BandWidth with range position"
 DECLARE
   @symbol := 'BTC-USDT',
-  @history_start := dateadd('M', -6, now()),
-  @display_start := dateadd('M', -1, now())
+  @history := '$now - 6M..$now',
+  @display := '$now - 1M..$now'
 
 WITH daily_ohlc AS (
   SELECT
@@ -38,7 +38,7 @@ WITH daily_ohlc AS (
     last(close) AS close
   FROM trades_ohlc_15m
   WHERE symbol = @symbol
-    AND timestamp > @history_start
+    AND timestamp IN @history
   SAMPLE BY 1d
 ),
 bands AS (
@@ -102,11 +102,11 @@ SELECT
   round(bandwidth, 4) AS bandwidth,
   round((bandwidth - min_bw) / (max_bw - min_bw) * 100, 1) AS range_position
 FROM with_range
-WHERE timestamp > @display_start
+WHERE timestamp IN @display
 ORDER BY timestamp;
 ```
 
-The query first aggregates 15-minute candles into daily OHLC, then calculates standard 20-day Bollinger Bands. This matches the traditional approach where SMA20 represents roughly one month of trading. The 6-month lookback (`@history_start`) establishes the historical range, while `@display_start` limits output to the last month. Standard deviation uses the variance formula `sqrt(avg(x²) - avg(x)²)`.
+The query first aggregates 15-minute candles into daily OHLC, then calculates standard 20-day Bollinger Bands. This matches the traditional approach where SMA20 represents roughly one month of trading. The 6-month lookback (`@history`) establishes the historical range, while `@display` limits output to the last month. Standard deviation uses the variance formula `sqrt(avg(x²) - avg(x)²)`.
 
 The `range_position` shows where current BandWidth falls within the 6-month range: 0% means at the historical minimum, 100% at the maximum. This works well for identifying squeeze conditions since you're comparing against historical extremes.
 
diff --git a/documentation/cookbook/sql/finance/liquidity-comparison.md b/documentation/cookbook/sql/finance/liquidity-comparison.md
index 282779e35..ba5d5c497 100644
--- a/documentation/cookbook/sql/finance/liquidity-comparison.md
+++ b/documentation/cookbook/sql/finance/liquidity-comparison.md
@@ -18,7 +18,7 @@ You have order book snapshots for multiple instruments and want to compare which
 WITH latest_books AS (
   SELECT timestamp, symbol, bids, asks
   FROM market_data
-  WHERE timestamp IN today()
+  WHERE timestamp IN '$today'
   LATEST ON timestamp PARTITION BY symbol
 )
 SELECT
@@ -49,7 +49,7 @@ SELECT
   last((L2PRICE(100_000, asks[2], asks[1]) - L2PRICE(100_000, bids[2], bids[1])) /
     ((L2PRICE(100_000, asks[2], asks[1]) + L2PRICE(100_000, bids[2], bids[1])) / 2)) * 10_000 AS spread_bps
 FROM market_data
-WHERE timestamp IN today()
+WHERE timestamp IN '$today'
   AND symbol IN ('EURUSD', 'GBPUSD', 'USDJPY')
 SAMPLE BY 1h
 ORDER BY timestamp, symbol;
@@ -63,7 +63,7 @@ See how execution costs scale with order size:
 WITH latest_books AS (
   SELECT symbol, bids, asks
   FROM market_data
-  WHERE timestamp IN today()
+  WHERE timestamp IN '$today'
   LATEST ON timestamp PARTITION BY symbol
 )
 SELECT
diff --git a/documentation/cookbook/sql/finance/ohlc.md b/documentation/cookbook/sql/finance/ohlc.md
index 68998c881..094ddd489 100644
--- a/documentation/cookbook/sql/finance/ohlc.md
+++ b/documentation/cookbook/sql/finance/ohlc.md
@@ -22,7 +22,7 @@ SELECT
   last(price) AS close,
   sum(quantity) AS total_volume
 FROM fx_trades
-WHERE timestamp IN today()
+WHERE timestamp IN '$today'
 SAMPLE BY 1m;
 ```
 
diff --git a/documentation/cookbook/sql/finance/rolling-stddev.md b/documentation/cookbook/sql/finance/rolling-stddev.md
index 1248f01e5..cf6c95edf 100644
--- a/documentation/cookbook/sql/finance/rolling-stddev.md
+++ b/documentation/cookbook/sql/finance/rolling-stddev.md
@@ -25,7 +25,7 @@ WITH stats AS (
     AVG(price) OVER (PARTITION BY symbol ORDER BY timestamp) AS rolling_avg,
     AVG(price * price) OVER (PARTITION BY symbol ORDER BY timestamp) AS rolling_avg_sq
   FROM fx_trades
-  WHERE timestamp IN yesterday() AND symbol = 'EURUSD'
+  WHERE timestamp IN '$yesterday' AND symbol = 'EURUSD'
 )
 SELECT
   timestamp,
diff --git a/documentation/cookbook/sql/finance/tick-trin.md b/documentation/cookbook/sql/finance/tick-trin.md
index 437ccb54d..694b94133 100644
--- a/documentation/cookbook/sql/finance/tick-trin.md
+++ b/documentation/cookbook/sql/finance/tick-trin.md
@@ -22,7 +22,7 @@ WITH with_previous AS (
   SELECT timestamp, symbol, price,
     LAG(price) OVER (PARTITION BY symbol ORDER BY timestamp) AS prev_price
   FROM fx_trades
-  WHERE timestamp IN today()
+  WHERE timestamp IN '$today'
 ),
 classified AS (
   SELECT  symbol,
@@ -64,7 +64,7 @@ WITH daily_stats AS (
     last(price) AS current_price,
     sum(quantity) AS total_volume
   FROM fx_trades
-  WHERE timestamp IN today()
+  WHERE timestamp IN '$today'
   SAMPLE BY 1d
 ),
 classified AS (
@@ -94,7 +94,7 @@ WITH candles AS (
     last(price) AS close_price,
     sum(quantity) AS total_volume
   FROM fx_trades
-  WHERE timestamp IN today()
+  WHERE timestamp IN '$today'
   SAMPLE BY 5m
 ),
 with_previous AS (
diff --git a/documentation/cookbook/sql/finance/volume-profile.md b/documentation/cookbook/sql/finance/volume-profile.md
index 5ce2d184d..cd5adfea6 100644
--- a/documentation/cookbook/sql/finance/volume-profile.md
+++ b/documentation/cookbook/sql/finance/volume-profile.md
@@ -17,7 +17,7 @@ SELECT
   round(SUM(quantity), 2) AS volume
 FROM fx_trades
 WHERE symbol = 'EURUSD'
-  AND timestamp IN today()
+  AND timestamp IN '$today'
 ORDER BY price_bin;
 ```
 
@@ -31,7 +31,7 @@ For consistent histograms across different price ranges, calculate the tick size
 WITH raw_data AS (
   SELECT price, quantity
   FROM fx_trades
-  WHERE symbol = 'EURUSD' AND timestamp IN today()
+  WHERE symbol = 'EURUSD' AND timestamp IN '$today'
 ),
 tick_size AS (
   SELECT (max(price) - min(price)) / 49 as tick_size
diff --git a/documentation/cookbook/sql/finance/volume-spike.md b/documentation/cookbook/sql/finance/volume-spike.md
index d1f860c1d..736a326fc 100644
--- a/documentation/cookbook/sql/finance/volume-spike.md
+++ b/documentation/cookbook/sql/finance/volume-spike.md
@@ -16,8 +16,7 @@ Use the `LAG` window function to retrieve the previous candle's volume, then com
 
 ```questdb-sql demo title="Detect volume spikes exceeding 2x previous volume"
 DECLARE
-  @anchor_date := timestamp_floor('30s', now()),
-  @start_date := dateadd('h', -7, @anchor_date),
+  @range := '$now - 7h..$now',
   @symbol := 'EURUSD'
 WITH candles AS (
   SELECT
@@ -25,7 +24,7 @@ WITH candles AS (
     symbol,
     sum(quantity) AS volume
   FROM fx_trades
-  WHERE timestamp >= @start_date
+  WHERE timestamp IN @range
     AND symbol = @symbol
   SAMPLE BY 30s
 ),
diff --git a/documentation/cookbook/sql/finance/vwap.md b/documentation/cookbook/sql/finance/vwap.md
index b92031149..4f3e6776f 100644
--- a/documentation/cookbook/sql/finance/vwap.md
+++ b/documentation/cookbook/sql/finance/vwap.md
@@ -28,30 +28,27 @@ WITH sampled AS (
     total_volume,
     ((high + low + close) / 3) * total_volume AS traded_value
   FROM fx_trades_ohlc_1m
-  WHERE timestamp IN yesterday() AND symbol = 'EURUSD'
-),
-cumulative AS (
-  SELECT
-    timestamp, symbol,
-    SUM(traded_value) OVER (ORDER BY timestamp) AS cumulative_value,
-    SUM(total_volume) OVER (ORDER BY timestamp) AS cumulative_volume
-  FROM sampled
+  WHERE timestamp IN '$yesterday' AND symbol = 'EURUSD'
 )
-SELECT timestamp, symbol, cumulative_value / cumulative_volume AS vwap
-FROM cumulative;
+SELECT
+  timestamp, symbol,
+  SUM(traded_value) OVER (ORDER BY timestamp) /
+    SUM(total_volume) OVER (ORDER BY timestamp) AS vwap
+FROM sampled;
 ```
 
 This query:
 1. Reads 1-minute OHLC candles and calculates typical price × volume for each candle
-2. Uses window functions to compute running totals of both traded value and volume
-3. Divides cumulative traded value by cumulative volume to get VWAP at each timestamp
+2. Divides cumulative traded value by cumulative volume using window functions
 
 ## How it works
 
-The key insight is using `SUM(...) OVER (ORDER BY timestamp)` to create running totals:
-- `cumulative_value`: Running sum of (typical price × volume) from market open
-- `cumulative_volume`: Running sum of volume from market open
-- Final VWAP: Dividing these cumulative values gives the volume-weighted average at each point
+The key insight is using `SUM(...) OVER (ORDER BY timestamp)` to create running totals, then dividing them directly:
+
+```sql
+SUM(traded_value) OVER (ORDER BY timestamp) /
+  SUM(total_volume) OVER (ORDER BY timestamp) AS vwap
+```
 
 When using `SUM() OVER (ORDER BY timestamp)` without specifying a frame clause, QuestDB defaults to summing from the first row to the current row, which is exactly what we need for cumulative VWAP.
 
@@ -66,33 +63,29 @@ WITH sampled AS (
     total_volume,
     ((high + low + close) / 3) * total_volume AS traded_value
   FROM fx_trades_ohlc_1m
-  WHERE timestamp IN yesterday()
+  WHERE timestamp IN '$yesterday'
     AND symbol IN ('EURUSD', 'GBPUSD', 'USDJPY')
-),
-cumulative AS (
-  SELECT
-    timestamp, symbol,
-    SUM(traded_value) OVER (PARTITION BY symbol ORDER BY timestamp) AS cumulative_value,
-    SUM(total_volume) OVER (PARTITION BY symbol ORDER BY timestamp) AS cumulative_volume
-  FROM sampled
 )
-SELECT timestamp, symbol, cumulative_value / cumulative_volume AS vwap
-FROM cumulative;
+SELECT
+  timestamp, symbol,
+  SUM(traded_value) OVER (PARTITION BY symbol ORDER BY timestamp) /
+    SUM(total_volume) OVER (PARTITION BY symbol ORDER BY timestamp) AS vwap
+FROM sampled;
 ```
 
-The `PARTITION BY symbol` ensures each symbol's VWAP is calculated independently, resetting the cumulative sums for each symbol.
+The `PARTITION BY symbol` ensures each symbol's VWAP is calculated independently.
 
 ## Different time ranges
 
 ```sql
 -- Current trading day
-WHERE timestamp IN today()
+WHERE timestamp IN '$today'
 
 -- Specific date
 WHERE timestamp IN '2026-01-12'
 
 -- Last hour
-WHERE timestamp >= dateadd('h', -1, now())
+WHERE timestamp IN '$now - 1h..$now'
 ```
 
 :::tip Trading use cases
diff --git a/documentation/cookbook/sql/time-series/elapsed-time.md b/documentation/cookbook/sql/time-series/elapsed-time.md
new file mode 100644
index 000000000..71751defd
--- /dev/null
+++ b/documentation/cookbook/sql/time-series/elapsed-time.md
@@ -0,0 +1,56 @@
+---
+title: Elapsed time between rows
+sidebar_label: Elapsed time
+description: Calculate the time elapsed between consecutive rows using lag() and datediff()
+---
+
+Calculate the time gap between consecutive events. Useful for detecting delays, measuring inter-arrival times, or identifying gaps in data streams.
+
+## Problem
+
+You want to know how much time passed between each row and the previous one, for example to spot gaps in a data feed or measure event frequency.
+
+## Solution
+
+```questdb-sql demo title="Elapsed time between consecutive trades"
+SELECT
+  timestamp,
+  lag(timestamp) OVER (ORDER BY timestamp) AS prev_timestamp,
+  datediff('T', timestamp, lag(timestamp) OVER (ORDER BY timestamp)) AS elapsed_millis
+FROM trades
+WHERE symbol = 'BTC-USDT'
+  AND timestamp IN '$today'
+LIMIT 20;
+```
+
+The `datediff('T', timestamp, prev_timestamp)` function returns the difference in milliseconds. Change the unit to control precision:
+
+| Unit | Description |
+|------|-------------|
+| `'s'` | Seconds |
+| `'T'` | Milliseconds |
+| `'U'` | Microseconds |
+
+## Raw timestamp subtraction
+
+If you subtract timestamps directly instead of using `datediff`, the result is in the **native resolution of the column** (microseconds for `TIMESTAMP`, nanoseconds for `TIMESTAMP_NS`):
+
+```questdb-sql demo title="Raw difference in microseconds"
+SELECT
+  timestamp,
+  timestamp - lag(timestamp) OVER (ORDER BY timestamp) AS elapsed_micros
+FROM trades
+WHERE symbol = 'BTC-USDT'
+  AND timestamp IN '$today'
+LIMIT 20;
+```
+
+:::note TIMESTAMP vs TIMESTAMP_NS
+The `trades` table uses `TIMESTAMP` (microsecond precision), so subtraction gives microseconds. Tables like `fx_trades` use `TIMESTAMP_NS` (nanosecond precision), where subtraction gives nanoseconds.
+:::
+
+:::info Related documentation
+- [lag() function](/docs/query/functions/window-functions/reference/#lag)
+- [datediff() function](/docs/query/functions/date-time/#datediff)
+- [Designated timestamp](/docs/concepts/designated-timestamp/)
+:::
diff --git a/documentation/cookbook/sql/time-series/fill-from-one-column.md b/documentation/cookbook/sql/time-series/fill-from-one-column.md
index 7d4997bdf..b7b97a9a6 100644
--- a/documentation/cookbook/sql/time-series/fill-from-one-column.md
+++ b/documentation/cookbook/sql/time-series/fill-from-one-column.md
@@ -13,7 +13,7 @@ You have a query like this:
 ```questdb-sql demo title="SAMPLE BY with FILL(PREV)"
 SELECT timestamp, symbol, avg(bid_price) as bid_price, avg(ask_price) as ask_price
 FROM core_price
-WHERE symbol = 'EURUSD' AND timestamp IN today()
+WHERE symbol = 'EURUSD' AND timestamp IN '$today'
 SAMPLE BY 100T FILL(PREV, PREV);
 ```
 
@@ -22,7 +22,7 @@ But when there is an interpolation, instead of getting the PREV value for `bid_p
 ```sql
 SELECT timestamp, symbol, avg(bid_price) as bid_price, avg(ask_price) as ask_price
 FROM core_price
-WHERE symbol = 'EURUSD' AND timestamp IN today()
+WHERE symbol = 'EURUSD' AND timestamp IN '$today'
 SAMPLE BY 100T FILL(PREV(ask_price), PREV);
 ```
 
@@ -34,7 +34,7 @@ The only way to do this is in multiple steps within a single query: first get th
 WITH sampled AS (
   SELECT timestamp, symbol, avg(bid_price) as bid_price, avg(ask_price) as ask_price
   FROM core_price
-  WHERE symbol = 'EURUSD' AND timestamp IN today()
+  WHERE symbol = 'EURUSD' AND timestamp IN '$today'
   SAMPLE BY 100T FILL(null)
 ), with_previous_vals AS (
   SELECT *,
@@ -54,7 +54,7 @@ You can mark which rows were filled by adding a column that flags interpolated v
 WITH sampled AS (
   SELECT timestamp, symbol, avg(bid_price) as bid_price, avg(ask_price) as ask_price
   FROM core_price
-  WHERE symbol = 'EURUSD' AND timestamp IN today()
+  WHERE symbol = 'EURUSD' AND timestamp IN '$today'
   SAMPLE BY 100T FILL(null)
 ), with_previous_vals AS (
   SELECT *,
diff --git a/documentation/cookbook/sql/time-series/force-designated-timestamp.md b/documentation/cookbook/sql/time-series/force-designated-timestamp.md
index da49887ab..bd7d7cec6 100644
--- a/documentation/cookbook/sql/time-series/force-designated-timestamp.md
+++ b/documentation/cookbook/sql/time-series/force-designated-timestamp.md
@@ -18,7 +18,7 @@ SELECT
   bid_price
 FROM
   core_price
-WHERE timestamp IN today()
+WHERE timestamp IN '$today'
 LIMIT 10;
 ```
 
@@ -38,7 +38,7 @@ WITH t AS (
       bid_price
     FROM
       core_price
-    WHERE timestamp >= dateadd('h', -1, now())
+    WHERE timestamp IN '$now - 1h..$now'
     ORDER BY time
   ) TIMESTAMP (time)
 )
@@ -57,9 +57,9 @@ You can restore the designated timestamp by applying `ORDER BY` and then using `
 (
   SELECT * FROM
   (
-    SELECT timestamp, symbol FROM core_price WHERE timestamp >= dateadd('m', -1, now())
+    SELECT timestamp, symbol FROM core_price WHERE timestamp IN '$now - 1m..$now'
     UNION ALL
-    SELECT timestamp, symbol FROM core_price WHERE timestamp >= dateadd('m', -1, now())
+    SELECT timestamp, symbol FROM core_price WHERE timestamp IN '$now - 1m..$now'
   ) ORDER BY timestamp
 )
 TIMESTAMP(timestamp)
diff --git a/documentation/cookbook/sql/time-series/latest-n-per-partition.md b/documentation/cookbook/sql/time-series/latest-n-per-partition.md
index 13be6ca66..1090a8db0 100644
--- a/documentation/cookbook/sql/time-series/latest-n-per-partition.md
+++ b/documentation/cookbook/sql/time-series/latest-n-per-partition.md
@@ -17,7 +17,7 @@ You want to get the latest N rows for each distinct value in a column. For examp
 
 ```questdb-sql demo title="LATEST ON returns only 1 row per symbol"
 SELECT * FROM trades
-WHERE timestamp in today()
+WHERE timestamp IN '$today'
 LATEST ON timestamp PARTITION BY symbol;
 ```
 
@@ -33,7 +33,7 @@ WITH ranked AS (
     *,
     row_number() OVER (PARTITION BY symbol ORDER BY timestamp DESC) as rn
   FROM trades
-  WHERE timestamp in today()
+  WHERE timestamp IN '$today'
 )
 SELECT timestamp, symbol, side, price, amount
 FROM ranked
@@ -104,7 +104,7 @@ DECLARE @limit := 10
 WITH ranked AS (
   SELECT *, row_number() OVER (PARTITION BY symbol ORDER BY timestamp DESC) as rn
   FROM trades
-  WHERE timestamp >= dateadd('d', -1, now())
+  WHERE timestamp IN '$now - 1d..$now'
 )
 SELECT * FROM ranked WHERE rn <= @limit;
 ```
@@ -116,7 +116,7 @@ WITH ranked AS (
     *,
     row_number() OVER (PARTITION BY symbol ORDER BY timestamp DESC) as rn
   FROM trades
-  WHERE timestamp in today()
+  WHERE timestamp IN '$today'
     AND side = 'buy'  -- Additional filter before ranking
 )
 SELECT timestamp, symbol, side, price, amount
@@ -129,7 +129,7 @@ WHERE rn <= 5;
 WITH ranked AS (
   SELECT *, row_number() OVER (PARTITION BY symbol ORDER BY timestamp DESC) as rn
   FROM trades
-  WHERE timestamp in today()
+  WHERE timestamp IN '$today'
 )
 SELECT timestamp, symbol, price, rn as rank
 FROM ranked
@@ -165,7 +165,7 @@ LIMIT -100;
 WITH ranked AS (
   SELECT *, row_number() OVER (PARTITION BY symbol ORDER BY timestamp DESC) as rn
   FROM trades
-  WHERE timestamp in today()  -- Filter early
+  WHERE timestamp IN '$today'  -- Filter early
 )
 SELECT * FROM ranked WHERE rn <= 5;
 
@@ -174,13 +174,13 @@ WITH ranked AS (
   SELECT *, row_number() OVER (PARTITION BY symbol ORDER BY timestamp DESC) as rn
   FROM trades  -- No filter
 )
-SELECT * FROM ranked WHERE rn <= 5 AND timestamp in today();
+SELECT * FROM ranked WHERE rn <= 5 AND timestamp IN '$today';
 ```
 
 **Limit partitions:**
 ```sql
 -- Process only specific symbols
-WHERE timestamp in today()
+WHERE timestamp IN '$today'
   AND symbol IN ('BTC-USDT', 'ETH-USDT', 'SOL-USDT')
 ```
 
@@ -196,7 +196,7 @@ WITH ranked AS (
     price,
     row_number() OVER (PARTITION BY symbol ORDER BY timestamp DESC) as rn
   FROM trades
-  WHERE timestamp in today()
+  WHERE timestamp IN '$today'
 )
 SELECT
   symbol,
diff --git a/documentation/cookbook/sql/time-series/remove-outliers.md b/documentation/cookbook/sql/time-series/remove-outliers.md
index c7b2c84c1..f1d1c235c 100644
--- a/documentation/cookbook/sql/time-series/remove-outliers.md
+++ b/documentation/cookbook/sql/time-series/remove-outliers.md
@@ -21,7 +21,7 @@ SELECT
     max(price),
     sum(quantity) AS volume
 FROM fx_trades
-WHERE symbol = 'EURUSD' AND timestamp > dateadd('d', -14, now())
+WHERE symbol = 'EURUSD' AND timestamp IN '$now - 14d..$now'
 SAMPLE BY 1d;
 ```
 
@@ -42,7 +42,7 @@ WITH moving_trades AS (
       RANGE BETWEEN 7 days PRECEDING AND 1 day PRECEDING
     ) AS moving_avg_price
   FROM fx_trades
-  WHERE symbol = 'EURUSD' AND timestamp > dateadd('d', -21, now())
+  WHERE symbol = 'EURUSD' AND timestamp IN '$now - 21d..$now'
 )
 SELECT
     timestamp, symbol,
@@ -52,7 +52,7 @@ SELECT
     max(price),
     sum(quantity) AS volume
 FROM moving_trades
-WHERE timestamp > dateadd('d', -14, now())
+WHERE timestamp IN '$now - 14d..$now'
   AND moving_avg_price IS NOT NULL
   AND ABS(price - moving_avg_price) <= moving_avg_price * 0.01
 SAMPLE BY 1d;
diff --git a/documentation/cookbook/sql/time-series/sample-by-interval-bounds.md b/documentation/cookbook/sql/time-series/sample-by-interval-bounds.md
index 5f76d7067..6820fd781 100644
--- a/documentation/cookbook/sql/time-series/sample-by-interval-bounds.md
+++ b/documentation/cookbook/sql/time-series/sample-by-interval-bounds.md
@@ -25,7 +25,7 @@ SELECT
     max(price),
     sum(quantity) AS volume
 FROM fx_trades
-WHERE symbol = 'EURUSD' AND timestamp IN today()
+WHERE symbol = 'EURUSD' AND timestamp IN '$today'
 SAMPLE BY 15m;
 ```
 
diff --git a/documentation/cookbook/sql/time-series/session-windows.md b/documentation/cookbook/sql/time-series/session-windows.md
index c819cc6dd..f39c8c2d6 100644
--- a/documentation/cookbook/sql/time-series/session-windows.md
+++ b/documentation/cookbook/sql/time-series/session-windows.md
@@ -41,7 +41,7 @@ WITH prevEvents AS (
     lag(lock_status::int) -- lag doesn't support booleans, so we convert to 1 or 0
       OVER (PARTITION BY vehicle_id ORDER BY timestamp) as prev_status
   FROM vehicle_events
-  WHERE timestamp IN today()
+  WHERE timestamp IN '$today'
 ),
 ride_sessions AS (
   SELECT *,
@@ -154,7 +154,7 @@ WITH prevEvents AS (
     lag(lock_status::int) -- lag doesn't support booleans, so we convert to 1 or 0
       OVER (PARTITION BY vehicle_id ORDER BY timestamp) as prev_status
   FROM vehicle_events
-  WHERE timestamp >= dateadd('M', -3, now())
+  WHERE timestamp IN '$now - 3M..$now'
 ),
 ride_sessions AS (
   SELECT *,