In Preprocessing

Date.parse('2023-04-06T12:11:59+0300')/1000

Result: 1979703119

Valid result: 1680772319 (checked over browser js console)

Adding  ":" to TZ part (2023-04-06T12:11:59+03:00) will fix this problem

https://en.wikipedia.org/wiki/ISO_8601

Time offsets from UTC[edit

The UTC offset is appended to the time in the same way that 'Z' was above, in the form ±[hh]:[mm], ±[hh][mm], or ±[hh].

Negative UTC offsets describe a time zone west of UTC±00:00, where the civil time is behind (or earlier) than UTC so the zone designator will look like "−03:00","−0300", or "−03"

Positive UTC offsets describe a time zone at or east of UTC±00:00, where the civil time is the same as or ahead (or later) than UTC so the zone designator will look like "+02:00","+0200", or "+02".​