create due .123Z (answer)          201 "2026-11-01T10:20:30.123Z"
read after create                  200 "2026-11-01T10:20:30Z"
patch due .456Z (answer)           200 "2026-12-01T00:00:00.456Z"
read after patch                   200 "2026-12-01T00:00:00Z"
patch due .000Z (answer)           200 "2026-12-01T00:00:00Z"
read after .000Z                   200 "2026-12-01T00:00:00Z"
list due_date                      200 ["2026-12-01T00:00:00Z"]
