Just so we have this straight...which users from your ban file were banned in the past few days, but, are XGUI is stating they were banned (and ban expiry) few months past?
And, are you getting the same 'calctime' error as the original poster listed?
The only 'oddity' I see are the last two bans of your file, which state ban time and expiration time are both one and same (individually).
"unban" "1376692494"
"time" "1376092494"
"name" "kleo1234"
That time = Fri, 16 Aug 2013 22:34:54 GMT according to Epochconverter.com
"unban" "1378259843"
"time" "1375667843"
"name" "Hank Hill"
That time = Mon, 05 Aug 2013 01:57:23 GMT according to epochconverter.com
I've not loaded in Gmod, but wanted to know bit more detail first.