What is the time format in the Slack API?

Question

Working with date/time

When an event occurs, Slack sends json. Among other things, this json has an event_ts field of this format - 1596302319.003500 . The numbers before the dot are the unix timestamp.
Question - what are these numbers after the dot? At first I thought it was milliseconds, but then there should have been 4 digits after the dot. After all, there are 1000 milliseconds in 1 second.

Answer 1

These are microseconds.