Quick Answer

Your goal in the first Palace is to secure the infiltration route early, then schedule the Calling Card and boss day. Do not spread Palace progress across too many free days if you can avoid it.

Calendar Logic

StageAction
First visitsLearn weaknesses, All-Out Attacks, and SP pressure
Mid routePush meaningful progress in each Palace day
Route securedLeave time for Calling Card and boss
After PalaceReturn calendar time to Confidants and social stats

Common Problems

ProblemAdjustment
SP runs outUse weaknesses, guns, items, and fewer wasteful casts
Too many returns homePlan deeper pushes instead of tiny progress chunks
Deadline anxietySecure the route before the final days
Boss feels roughCheck gear, healing items, and Persona resistances