A static-html timezone calculator you can save and use offline.

https://akkartik.name/tz.html

https://akkartik.name/tz-dst.html

Expected usage:
* Someone gives you a time and timezone.
* Scroll to the row for the timezone.
* Click on the column corresponding to the hour for the time to highlight the
entire column.
* Scroll to the row for your home timezone (the difficulty of doing this might
affect which of the above links you use)
* Read the hour off the highlighted column, or calculate the hour based on the
column in nearby rows.
* Adjust the time for minutes.

Send bug reports to https://akkartik.name/contact