There is no single correct number of days, and any answer that gives you one is guessing. There is, however, a shape most adjustments follow, and knowing the shape helps more than a fake number would.
In the same classroom, on the same schedule, one two-year-old settles inside a week and another takes most of a term. Temperament, prior experience with separation, and the consistency of the caregivers in the room all matter more than the calendar date on the enrollment form.
Usually the hardest. Everything is unfamiliar — the room, the smell, the faces, the routine — and a two-year-old has no evidence yet that this new place reliably ends with you coming back. This is where the most tears show up, and it is not a preview of how the whole experience will go.
The room starts to become familiar even before the tears fully stop. Staff often notice a child settling into an activity faster after you leave, even on days the goodbye itself is still hard. Ask the teacher directly what they are seeing during the day, not just at the door — the two pictures are often very different.
For many two-year-olds the daily transition gets noticeably easier around this point, though occasional hard mornings — after a weekend, after being sick, after a holiday — stay normal well beyond this. A rough Monday after three easy weeks is not a step backward.
Rarely zero tears forever. More often: shorter tears, less frequent hard mornings, and a child who settles into the room quickly once you are gone. Ask the room for that specific detail — how long does it take him to settle, not whether he ever cries — because that is the number that actually tracks adjustment.
Not unusual for some children, and on its own is not a sign of a problem. What is worth a direct conversation with the teacher is no change at all over that length of time — not shorter, not less frequent.
There is no reliable single answer here — temperament and prior separation experience appear to matter more than age alone. Treat any confident claim about age and adjustment speed with real skepticism.
Some re-settling after an absence — illness, a vacation, a long weekend — is common, and it is usually shorter than the very first adjustment.
Part of our guide to Starting daycare.