I see the cache and fresh date update just before midnight most nights. The cache date/time is usually from just 18 to 22 hours ago.
In the past if the Cache date/time was between 00:00 and 06:00 UTC/GMT then the Fresh date would be reported as one day earlier because the Fresh Date is aligned to some US time zone.
As of today I am seeing a Cache date/time from 48 hours ago, and the Fresh date is the same date this time.
It looks like Fresh dates might be aligned to GMT rather than to a US time zone now (or it might be that the Fresh date has just changed and the Cache is just about to update again, and that I am wrong).
Why does Google continue to use the term GMT? That term was hanged to be UTC way back in 1971.