diff --git a/util.go b/util.go
new file mode 100644
index 0000000..a2ab8af
--- /dev/null
+++ b/util.go
@@ -0,0 +1,15 @@
+package main
+
+import (
+	"time"
+)
+
+func toDate(d uint32) time.Time {
+	t, _ := time.Parse("2006-01-02T15:04:05+07:00", "0001-01-01 00:00:00+00:00")
+	t = t.AddDate(0, 0, int(d))
+	return t
+}
+
+func fromDate(t time.Time) uint32 {
+	return 0
+}