The region where I am located does not use DST. Inspired by Matt Johnson-Pint's answer, I made the package Which Hemisphere. It is neither based on Moment.js nor DST, but rather based on builtin Intl.

Due to its size, I did not paste it here. The implementation principle is to obtain the time zone name by Intl.DateTimeFormat().resolvedOptions().timeZone, and return the result based on the time zone name.