FM 3-05 Chapter 3 · Time and dates
Windows and other epochs
FILETIME, AD lastLogonTimestamp, Excel serials, .NET ticks, GPS, NTP, Cocoa, snowflake ids, UUID and ULID times.
Local only Runs in your browser. Nothing you enter leaves this page.
Usable as a step in ChainAD stores lastLogonTimestamp, pwdLastSet, accountExpires and badPasswordTime as FILETIME: 100 ns
steps since 1601-01-01 UTC. On Windows, w32tm /ntte does the same conversion. lastLogonTimestamp
only replicates when it is 9 to 14 days old, so it can lag by two weeks.
Excel's 1900 system counts 1900-02-29, a day that never existed, so serials before 61 are one day off from a plain day count. GPS time ignores leap seconds: GPS − UTC is 18 s since 2017-01-01 (IERS Bulletin C). NTP seconds wrap in 2036; the hex form is 32-bit seconds and 32-bit fraction.
Snowflake ids hold milliseconds since a service epoch in the top 42 bits: X / Twitter 1288834974657 (2010-11-04), Discord 1420070400000 (2015-01-01). Given a date, the tool shows the lowest id for that millisecond, useful for since_id style range queries.