Date and time in one control

Expected: the first control shows 15 September 2026, 10:35, and its picker offers both a calendar and a time; changing either updates the control live. The empty control opens on now. Cancel restores the original; OK keeps the choice.

Bounds cover both halves

Expected: the calendar greys out days outside 10–20 September 2026, and on the 10th and 20th the time is limited to what the bound allows (from 09:00 on the 10th, up to 17:00 on the 20th).

Readonly, disabled and invalid values

Expected: readonly and disabled open nothing. The invalid values are sanitised to empty: a date alone, a time alone, or a bad date are not a valid local date-time.