Hi peeps,
I ORD in September this year. my unit wants us to apply ALL leave
by June (before 3 months before we ORD).
We cannot take leave during the last 2 weeks prior to ORD.
Is this a standard practice? My friend in another unit can take/
keep leave up to his very last week... 
It is not a standard policy, and it is up to your unit.
The only standard policy is that NSFs are not allowed to take
continuous leaves/OIL for more than 2 weeks in a row just prior to
ORD. And by 2 weeks, it includes weekend.