Ok, so I did this:
[cb:parse function="time"][cb:date format="Y-m-d" /][/cb:parse] GREATER THAN OR EQUAL TO [cb:parse function="time"][cb:date format="Y" /]-11-30[/cb:parse]

That seems to show something reasonable, allthough it's quite hard to interpret the numbers, but do I need to enter the offset here?

I tried changing it to
[cb:parse function="time"]now[cb:date format="Y-m-d" /][/cb:parse] GREATER THAN OR EQUAL TO [cb:parse function="time"]now[cb:date format="Y" /]-11-30[/cb:parse]
But I don't see any difference with or without the 'now' in there?

I found another comparison I need to look at, I got this from you guys last year, it is supposed to tell me id a member is 12 years old or more:

[cb:parse function="date" date-format="Y" time="false"][cb:parse function="time" time="+12 YEARS"][cb_birthday][/cb:parse][/cb:parse] LESS THAN OR EQUAL TO [cb:parse function="date" date-format="Y" time="false"][/cb:parse]

Should I just enter now in the latter:

[cb:parse function="date" date-format="Y" time="false"][cb:parse function="time" time="+12 YEARS"][cb_birthday][/cb:parse][/cb:parse] LESS THAN OR EQUAL TO [cb:parse function="date" date-format="Y" time="false"]now[/cb:parse]

Ok, that looks ok. Allthough both of them are delivered in UTC, I found an epoch converter that could show the right date. But as they are both in UTC, the difference is the same on both sides.
But that got me thinking about the other comparisons.
Becauce I'm in UTC+2 I need to trigger all the datecomparisons AFTER 02.00 at night?