Table of integers and how they convert into timestamps at different resolutions.
A ✓
indicates the timestamp is within the range 0000-00-00T00:00:00Z to 9999-12-31T23:59:59.9999 which is considered valid by Google BigQuery.
The number 253402300799
is the unix timestamp (number of seconds since 1970-01-01T00:00:00Z) until 9999-12-31T23:59:59.9999 and is the recommended switch to the next resolution.
input @ unit = time | input * 1ns | input * 1µs | input * 1ms | input * 1s
-9223372036854775808 @ 1ns = 1677-09-21T00:12:43Z | 1677-09-21T00:12:43Z ✓ | -290308-12-21T19:59:05Z | -292275055-05-16T16:47:04Z | 292277026596-12-04T15:30:08Z
-62135596800000000 @ 1µs = 0001-01-01T00:00:00Z | 1968-01-12T20:06:43Z ✓ | 0001-01-01T00:00:00Z ✓ | -1967029-04-28T00:00:00Z | -1968996709-01-15T00:00:00Z