Origin defines the starting point and duration specifies the size of the time intervals it will create.
If origin is 2023-01-01 043000 and duration is 3600000 ms you will get hourly intervals like:
2023-01-01 043000 - 2023-01-01 053000
2023-01-01 053000 - 2023-01-01 063000
2023-01-01 063000 - 2023-01-01 073000
Notice that origin can be set to any time.