It’s just a strange syntax for specifying date format… think 1, 2, 3, 4, 5, 6, 7:
| Number | Meaning | Examples |
|---|---|---|
| 1 | month | 01, Jan, January |
| 2 | day | 02, Mon, Monday |
| 3 | hour | 03, 15 |
| 4 | minute | 04 |
| 5 | seconds | 05 |
| 6 | year | 06, 2006 |
| 7 | timezone | -0700, -07:00, -07, MST |
References:
Update: Just blogged about this – Time formatting in Go