Finding ones that are forum compatible is a bit of a pain, so here we are
MotionMailApp.com
Nice and hackable because there is lots of data encoded in the URL. It’s an animated gif generated server-side.
Only has 45 seconds of frames though.
Requires a login to generated, but once you have a look at the URL you’ll never have to sign in again.
Pending.me.uk
This one isn’t animated, but it does display the end time in a bunch of timezones. Refresh the page to update it
Anyone know any other sources for embeddable timers?