What does my browser think?
When a user reports “the time shows wrong for me”, send them this link and ask for a screenshot (or the copy-paste report at the bottom). It shows everything their browser believes about locale, time zone and clock — which is where these bugs almost always live.
Intl resolved options
Date object & environment
Next DST transition (your zone)
Clock skew vs server
Measuring…
The same instant, in different locales
Copy-paste report
Everything above as plain text, for bug reports: