FoxClocks

Fox Clocks is a handy little addon for firefox. It can display multiple clocks around the world so you can see the local time in any chosen city.

I thought there was a problem with the daylights saving time bevahiour of FoxClocks.

I'm using version 2.9.35. It was reporting my local time correctly, but 2 days ago the US had their daylights savings time adjustment, while in Europe we are not having ours for 2 more weeks.

My time was been reported corectly, but my US based FoxClocks were not. They were still showing the old pre-Daylight Savings time.

The problem is because that FoxClocks uses an internal database of when daylights saving events occur. I simply had to update that database using Tools/ Options/ Time Zone Data/ Check Now.
When this is done it displayed the correct US times.