Initial commit

server/internal/gametime/gametime.go

@@ -0,0 +1,27 @@
+package gametime
+
+import "time"
+
+func Now() time.Time {
+	return time.Now().UTC()
+}
+
+func NowMillis() int64 {
+	return Now().UnixMilli()
+}
+
+func StartOfDayMillis() int64 {
+	n := Now()
+	return time.Date(n.Year(), n.Month(), n.Day(), 0, 0, 0, 0, time.UTC).UnixMilli()
+}
+
+// WeeklyVersion returns a stable weekly identifier (start-of-week timestamp in millis, Monday 00:00 UTC).
+func WeeklyVersion(millis int64) int64 {
+	t := time.UnixMilli(millis).UTC()
+	weekday := int(t.Weekday())
+	if weekday == 0 {
+		weekday = 7
+	}
+	monday := time.Date(t.Year(), t.Month(), t.Day()-(weekday-1), 0, 0, 0, 0, time.UTC)
+	return monday.UnixMilli()
+}