I have a piece of paper on my desk, each side has the time zone, utc offset, and date when DST will change. Twice a year I flip over the paper.

Right now it reads "EDT, UTC-4, until: Sun, Nov 2"

Going to add a clock next to it now, that's a great idea

  $ zdump -Vc 2025,2026 America/New_York
  America/New_York  Sun Mar  9 06:59:59 2025 UT = Sun Mar 9 01:59:59 2025 EST isdst=0 gmtoff=-18000
  America/New_York  Sun Mar  9 07:00:00 2025 UT = Sun Mar 9 03:00:00 2025 EDT isdst=1 gmtoff=-14400
  America/New_York  Sun Nov  2 05:59:59 2025 UT = Sun Nov 2 01:59:59 2025 EDT isdst=1 gmtoff=-14400
  America/New_York  Sun Nov  2 06:00:00 2025 UT = Sun Nov 2 01:00:00 2025 EST isdst=0 gmtoff=-18000

  $ zdump -Vc 2025,2026 Europe/London
  Europe/London  Sun Mar 30 00:59:59 2025 UT = Sun Mar 30 00:59:59 2025 GMT isdst=0 gmtoff=0
  Europe/London  Sun Mar 30 01:00:00 2025 UT = Sun Mar 30 02:00:00 2025 BST isdst=1 gmtoff=3600
  Europe/London  Sun Oct 26 00:59:59 2025 UT = Sun Oct 26 01:59:59 2025 BST isdst=1 gmtoff=3600
  Europe/London  Sun Oct 26 01:00:00 2025 UT = Sun Oct 26 01:00:00 2025 GMT isdst=0 gmtoff=0

And then with distributed team you realize DST change dates are different around the globe.

Desks around the globe can have different pieces of paper.