What the window really is
For four weeks in late summer, families reset. New schedules, new commitments, new appointments, deferred maintenance finally addressed before the year gets busy. Decisions that sat idle all summer get made quickly.
Retail understands this and spends accordingly. Local service businesses mostly ignore it, which is exactly why it is cheap.
Categories it applies to
Medical and dental — physicals, checkups, orthodontics, anything requiring appointments that fit a school schedule. Auto — second vehicles, tires, service before the commute season. Home services — the last window before autumn.
Also: fitness, tutoring and enrichment, cleaning services, family photography, pet care, and anything a parent puts off until the household has a routine again.
If your customer is a household with children, the window is yours.
Timing and messaging
Start two weeks before local schools return and run two weeks past. Check your district calendar rather than assuming a national date — in a county-level campaign, that detail matters.
Message to the routine, not to school. "Before the schedule gets busy" beats anything with a backpack in it. Appointment availability and evening or weekend hours are the strongest hooks.
Why it stays cheap
Because the businesses who could use it think it belongs to retail. Auction prices in service categories barely move during these weeks, which means you get an unusually motivated audience at ordinary cost.
That combination is rare enough to put in the calendar permanently.