all time calculations done within database

server/db.go

@@ -6,7 +6,6 @@ import (
 	"log"
 	"net/url"
 	"os"
-	"time"
 
 	_ "github.com/go-sql-driver/mysql"
 )
@@ -25,13 +24,15 @@ func InitDB() {
 		return
 	}
 
-	log.Printf("[DB] Using timezone: %s (Local=%s)", os.Getenv("TZ"), time.Local.String())
-	// Default to UTC if TZ is empty, otherwise use the encoded TZ name
-	tzParam := "UTC"
-	if os.Getenv("TZ") != "" {
-		tzParam = url.QueryEscape("'" + os.Getenv("TZ") + "'")
+	// Use TZ env var if set, otherwise fallback to Local
+	location := "Local"
+	tz := os.Getenv("TZ")
+
+	dsn := fmt.Sprintf("%s:%s@tcp(%s:%s)/%s?parseTime=true&loc=%s", user, pass, host, port, name, location)
+	if tz != "" {
+		dsn += fmt.Sprintf("&time_zone='%s'", url.QueryEscape(tz))
 	}
-	dsn := fmt.Sprintf("%s:%s@tcp(%s:%s)/%s?parseTime=true&loc=Local&time_zone=%s", user, pass, host, port, name, tzParam)
+
 	var err error
 	db, err = sql.Open("mysql", dsn)
 	if err != nil {
@@ -42,21 +43,7 @@ func InitDB() {
 		log.Fatalf("Error connecting to database: %v", err)
 	}
 
-	log.Println("Connected to MariaDB successfully")
-
-	// Verify and enforce timezones
-	var dbNow, dbTZ string
-	err = db.QueryRow("SELECT NOW(), @@session.time_zone").Scan(&dbNow, &dbTZ)
-	if err == nil {
-		log.Printf("[DB] Before setting: NOW()=%s, session.time_zone=%s", dbNow, dbTZ)
-	}
-
-	if _, err := db.Exec("SET time_zone = SYSTEM"); err != nil {
-		log.Printf("[DB] Warning: Failed to set session time_zone to SYSTEM: %v", err)
-	} else {
-		db.QueryRow("SELECT NOW(), @@session.time_zone").Scan(&dbNow, &dbTZ)
-		log.Printf("[DB] After setting: NOW()=%s, session.time_zone=%s", dbNow, dbTZ)
-	}
+	log.Printf("[DB] Connected to MariaDB successfully (using loc=%s, tz=%s)", location, tz)
 
 	createTables()
 }
@@ -108,8 +95,8 @@ func createTables() {
 			start_day_initial_steps INT,
 			previous_total_steps INT,
 			target_total_steps INT,
-			last_sync_time DATETIME,
-			next_sync_time DATETIME,
+			last_sync_time TIMESTAMP NULL,
+			next_sync_time TIMESTAMP NULL,
 			FOREIGN KEY (user_id) REFERENCES users(fitbit_user_id) ON DELETE CASCADE
 		)`,
 		`CREATE TABLE IF NOT EXISTS daily_steps (
@@ -126,5 +113,10 @@ func createTables() {
 			log.Fatalf("Error creating table: %v\nQuery: %s", err, query)
 		}
 	}
+
+	// Migrations: Ensure trips table uses TIMESTAMP for sync times (breaking change for DATETIME -> TIMESTAMP)
+	db.Exec("ALTER TABLE trips MODIFY last_sync_time TIMESTAMP NULL")
+	db.Exec("ALTER TABLE trips MODIFY next_sync_time TIMESTAMP NULL")
+
 	log.Println("Database tables initialized")
 }

server/step_manager.go

@@ -93,10 +93,6 @@ func (sm *StepManager) SaveTripState() {
 }
 
 func (sm *StepManager) saveTripStateLocked() {
-	fmt.Printf("[StepManager] Saving trip state for %s: StartTime=%v (%s), LastSync=%v (%s)\n",
-		sm.userID, sm.tripState.StartTime, sm.tripState.StartTime.Location(),
-		sm.lastSyncTime, sm.lastSyncTime.Location())
-
 	_, err := db.Exec(`
 		INSERT INTO trips (user_id, start_date, start_time, start_day_initial_steps, previous_total_steps, target_total_steps, last_sync_time, next_sync_time)
 		VALUES (?, ?, ?, ?, ?, ?, ?, ?)
@@ -248,6 +244,20 @@ func (sm *StepManager) performSync(interval time.Duration) {
 	sm.lastSyncTime = time.Now()
 	sm.nextSyncTime = time.Now().Add(interval)
 
+	// Save final state with explicit NOW() for last_sync_time to ensure DB consistency
+	// next_sync_time is also calculated in SQL relative to the same NOW()
+	_, err = db.Exec(`
+		UPDATE trips SET 
+			last_sync_time = NOW(),
+			next_sync_time = DATE_ADD(NOW(), INTERVAL ? SECOND),
+			previous_total_steps = ?,
+			target_total_steps = ?
+		WHERE user_id = ?
+	`, interval.Seconds(), sm.previousTotalSteps, sm.targetTotalSteps, sm.userID)
+	if err != nil {
+		fmt.Printf("Error saving sync completion: %v\n", err)
+	}
+
 	fmt.Printf("Sync Complete. Total Trip Steps: %d\n", sm.targetTotalSteps)
 }