Some of what Finncapt says is not quite correct.
Specifically
Assuming you have 29(?) days leave, 14(?) days duty free week, 4 sim days and 1 ground school (sep) day per year which attract 4½ hrs credit (216 hrs) you must do 829 other credited hours to achieve max pay.
You will therefore be hard pushed to do 900 flying hours without overtime.
That is wrong. You do not get 4.5 hours credit per day for leave and duty free weeks.
You get a number of hours credit that reflects the proportion of the month that you have the leave/duty free. So, if you have 7 days of leave or duty free in February you will achieve 7/28 of the CAP for that month, and if you have 14 days in July you will get 14/31 of the monthly CAP towards your target.
A weeks leave will get you approximately 20 hours (and not 7 x 4.5 = 31.5 hours) credit.
So, running the annual numbers:
30 days leave = c. 86 hours credit
14 days duty free = c. 40 hours credit
4 days sim = 18 hours credit
1 day sep = 5 hours credit
Adding those up gives 149 hours.
1051 hours annual credit (max) - 149 hours gives 902 hours credit available for flying!
In Longhaul, most trips are flying hour based credit, ie 1 for 1, so 900 hours is achievable without overtime unlike what Finncapt says.
Indeed, the timing of your leave from one year to the next can cause issues. Say you had leave in June this year and August next year, then the leave credit from ne is replaced by flying the next June and the 900 hour absolute limit can cause a bit problem which may well determine your bidding strategies!
[Edit to add - retired 2009 - more recently than Finncapt!]