Support TZ environment variable for timezone configuration

Dockerfile

@@ -29,7 +29,7 @@ RUN go build -o /app/app main.go
 # Runtime
 FROM alpine:3.19
 WORKDIR /app
-RUN apk add --no-cache sqlite-libs ca-certificates && \
+RUN apk add --no-cache sqlite-libs ca-certificates tzdata && \
     mkdir -p /data
 
 COPY --from=builder /app/app /app/app

README.md

@@ -31,6 +31,10 @@ BackApp supports the following command-line flags:
 - `-port` - Port to run the server on (default: `8080`)
 - `-db` - SQLite database path (default: `/data/app.db`)
 
+### Environment Variables
+
+- `TZ` - Set the timezone for the application (e.g., `Asia/Bangkok`, `America/New_York`, `Europe/London`). This affects all timestamps in logs, backup runs, and naming rules. If not set, the system default timezone (typically UTC in Docker) is used.
+
 Examples:
 ```bash
 # Run on a different port
@@ -41,6 +45,9 @@ Examples:
 
 # Combine multiple flags
 ./backapp -port=9090 -db=/custom/path/app.db
+
+# Set timezone using environment variable
+TZ=Asia/Bangkok ./backapp
 ```
 
 ## Quick start

docker-compose.yml

@@ -6,6 +6,9 @@ services:
       - "8080:8080"
     command: [ "-port=8080" ]
     restart: unless-stopped
+    # Optionally set timezone using TZ environment variable
+    # environment:
+    #   - TZ=Asia/Bangkok
     healthcheck:
       test: ["CMD-SHELL", "wget -qO- http://localhost:8080/health || exit 1"]
       interval: 30s

server/go.mod

@@ -3,6 +3,7 @@ module backapp-server
 go 1.24.0
 
 require (
+	github.com/SherClockHolmes/webpush-go v1.4.0
 	github.com/gin-gonic/gin v1.10.0
 	github.com/robfig/cron/v3 v3.0.1
 	golang.org/x/crypto v0.46.0
@@ -11,7 +12,6 @@ require (
 )
 
 require (
-	github.com/SherClockHolmes/webpush-go v1.4.0 // indirect
 	github.com/bytedance/sonic v1.12.3 // indirect
 	github.com/bytedance/sonic/loader v0.2.0 // indirect
 	github.com/cloudwego/base64x v0.1.4 // indirect

server/go.sum

@@ -30,8 +30,6 @@ github.com/goccy/go-json v0.10.3 h1:KZ5WoDbxAIgm2HNbYckL0se1fHD6rz5j4ywS6ebzDqA=
 github.com/goccy/go-json v0.10.3/go.mod h1:oq7eo15ShAhp70Anwd5lgX2pLfOS3QCiwU/PULtXL6M=
 github.com/golang-jwt/jwt/v5 v5.2.1 h1:OuVbFODueb089Lh128TAcimifWaLhJwVflnrgM17wHk=
 github.com/golang-jwt/jwt/v5 v5.2.1/go.mod h1:pqrtFR0X4osieyHYxtmOUWsAWrfe1Q5UVIyoH402zdk=
-github.com/google/go-cmp v0.5.5 h1:Khx7svrCpmxxtHBq5j2mp/xVjsi8hQMfNLvJFAlrGgU=
-github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
@@ -152,8 +150,6 @@ golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
 golang.org/x/tools v0.13.0/go.mod h1:HvlwmtVNQAhOuCjW7xxvovg8wbNq7LwfXh/k7wXUl58=
 golang.org/x/tools v0.21.1-0.20240508182429-e35e4ccd0d2d/go.mod h1:aiJjzUbINMkxbQROHiO6hDPo2LHcIPhhQsa9DLh0yGk=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
-golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/protobuf v1.35.2 h1:8Ar7bF+apOIoThw1EdZl0p1oWvMqTHmpA2fRTyZO8io=
 google.golang.org/protobuf v1.35.2/go.mod h1:9fA7Ob0pmnwhb644+1+CVWFRbNajQ6iRojtC/QF5bRE=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=

server/main.go

@@ -7,6 +7,8 @@ import (
 	"io/fs"
 	"log"
 	"net/http"
+	"os"
+	"time"
 
 	"backapp-server/config"
 	"backapp-server/controller"
@@ -36,6 +38,17 @@ func CORSMiddleware() gin.HandlerFunc {
 var embeddedStaticFiles embed.FS
 
 func main() {
+	// Load timezone from TZ environment variable
+	if tzEnv := os.Getenv("TZ"); tzEnv != "" {
+		loc, err := time.LoadLocation(tzEnv)
+		if err != nil {
+			log.Printf("Warning: Failed to load timezone '%s': %v. Using system default.", tzEnv, err)
+		} else {
+			time.Local = loc
+			log.Printf("Timezone set to: %s", tzEnv)
+		}
+	}
+
 	// Parse command line flags
 	port := flag.Int("port", 8080, "Port to run the server on")
 	dbPath := flag.String("db", "./app.db", "SQLite database path")