Fix case sensitivity for grain_to_date and offset_to_grain
#1120
| Job | Run time |
|---|---|
| 34s | |
| 35s | |
| 1m 9s |
grain_to_date and offset_to_grain
#1120
| Job | Run time |
|---|---|
| 34s | |
| 35s | |
| 1m 9s |