Avoid forcing the quickset
If the mechanism is binding or the watch is in its calendar-change window, forcing the crown can worsen the damage.
Describe exactly what fails
Does the date not advance at midnight? Does quickset fail? Does the day change but not the date? Does the crown slip between positions? Those details help.
Hands and calendar timing can interact
A watch that appears to change date at the wrong time may also have hand-indexing or prior assembly issues.
Movement-specific parts matter
The correct calendar components depend on the caliber and sometimes language/day-wheel configuration.