Added Unit of time enum

Author: Said Shah

src/enumerations/unit-of-time.ts

@@ -0,0 +1,20 @@
+enum UnitOfTime {
+    Day = "day",
+    Days = "days",
+    Hour = "hour",
+    Hours = "hours",
+    Millisecond = "millisecond",
+    Milliseconds = "milliseconds",
+    Minute = "minute",
+    Minutes = "minutes",
+    Month = "month",
+    Months = "months",
+    Second = "second",
+    Seconds = "seconds",
+    Week = "week",
+    Weeks = "weeks",
+    Year = "year",
+    Years = "years",
+}
+
+export { UnitOfTime };