US time is usually quoted as Eastern by my American colleagues (everybody west of New York and Washington DC adjusts). Currently Eastern time is 5 hours behind British Summertime here in the UK.
It’s pretty easy, Eastern is 1 hour ahead of Central, which is 1 hour ahead of Pacific (Los Angeles etc). That covers everybody except Hawaii and Alaksa (who confusingly have the a slightly different one each). Alaska is usually called Hawaii and Aleutian and runs at UTC-9, Hawaii runs at UTC -10.
The differences change with summertime daylight saving, so you get EDT (winter) and EST (summer).
