Unix timestamp

-1610841600

Mon 16 Dec 1918 12:00:00 AM UTC

Coordinated Universal Time

Mon Dec 16 00:00:00 1918 UTC

In your local timezone

1918-12-16T00:00:00+00:00

ISO 8601

Mon, 16 Dec 1918 00:00:00 +0000

RFC 2822