What is a timestamp? Three common formats explained
Those 10-digit or 13-digit numbers in your logs — telling seconds from milliseconds avoids half of the time zone pitfalls.
The scenario
With 1720000000 some people read it as milliseconds and some as seconds, and the results differ by decades.
The three formats
Unix seconds, Unix milliseconds and ISO 8601. The timestamp converter detects which one you have and shows both Beijing time and UTC.
Prefer storing UTC timestamps and convert to Asia/Shanghai only for display.