Sure April Fool la.

Obviously prank, Gen-X is famous for doing that.

depends on the bank.

these are the dates (could've a bit more) that i've gotten:

MBB Credit Card Bill Cycle Dates
3 6 8 12 14 18 21 24 26 28 EOM

HLB Credit Card Bill Cycle Dates
1 2 3 4 5 7 11 16 17 19 20 22 23 25 26 29 30 31

UOB VOX Card Bill Cycle Dates
3 13 14 15 16 17 21 23 24 25 26

you cant just pick a date the bank doesnt have, so pick something near your preferred PDD (payment due date).
fyi, PDD = bill date + 20 days.
imo, i prefer bill date in early of the month, so that PDD always on a fixed day within same month. e.g. bill date = 3, pdd = 23.

if my bill date slightly later, the pdd already cross to next month, hence always +/- 1 day difference, which is a annoying to track  . e.g. bill date = 15, pdd = 4 or 5, depending on the month. however, there is always a slight grace period of 1-2 days after PDD that you can still pay without getting interest charges.

if bill date on Feb, the pdd date in March will much further away since Feb has shorter day count
to track pdd, statement always stated the date.  or my simple rule: bill date & pdd = within same month.

When u mention limit is 1.1x your salary, u mean Annual Salary right?