Here at CX a week of leave is worth 14 credits........ 7 days times 2 credits per day. 14 credits toward an 84 hour month is only 17% of your month. Who negotiated this gem?
Since a week is roughly 1/4 of a month, one might think that a weeks leave would be worth something close to....... lets go out on a limb here...... 1/4 of a month's credit. At the very least a week's leave should work out to 7/31 x 84 or 19 credits.
The result of this is that in order to get "value" for your leave, you need to take it in large chunks, so that they can't fit a full month's flying into the remaining days.