I often time the start of auctions using Ebid Spreadsheet
Column I
Start immediate, on first bid or dd/mm/yyyy hh:mm.. Don't forget you can't auto-repost if using on first bid.
I have been over in America for three weeks and loaded some auctions during slack times there, and had to think about what dd/mm/yyyy hh:mm would be when I was located 8 hours behind British Summer Time.
I guessed that my auctions, loading in uk.ebid.net would be British Time, not local time.
Now I am wondering whether the time is fixed as GMT0, or whether it changes to Summer Time, GMT+1.
A note in Ebid Spreadsheet for Column I could explain what time Ebid uses for dd/mm/yyyy hh:mm for avoiding doubt.