72 Hours to drop via moving an X day and 0700 PCS the day prior to straight drop a reserve day.

See below from the scheduling reference handbook.

Scoop


X Day Move Rules
X days may be moved, at pilot request, via PCS under “leave requests,” provided:
• the X day(s) to be moved are:
o an entire X-day block,
o the first or last day of an X-day block, or
o a series of contiguous X days that includes the first or last day of an X-day block, and
• reserve availability in the category is sufficient, and
• movement of the X day(s) does not cause an FAR violation, and
• X day(s) are not moved into or out of a scheduled vacation, and
• X day(s) are not moved into or out of the last six days of the current bid period during the PBS bid award process for the subsequent bid period, and
• the X day(s) to be moved begin at least 72 hours after the award date of the move, and
• X day(s) are moved to be contiguous with:
o another X-day block,
o a training day,
o a vacation day,
o a PD/APD day, or
o a day of legal duty.