| 3M | Quarter |
| 6M | Half-year |
| AA | Air hour Flight duration irrespective of time zones. |
| AD | Air day Flight duration irrespective of time zones. |
| CD | Calendar day (includes weekends and holidays) Period given as a number of days including weekends and holidays. |
| CW | Calendar week (7day) Period given as a number of 7day-weeks including holidays. |
| D | Day |
| DC | Ten days period Period of 10 days. |
| DW | Work day |
| F | Period of two weeks Self-explanatory. |
| H | Hour |
| HM | Half month |
| M | Month |
| MN | Minute |
| P | Four month period |
| S | Second |
| SD | Surface day Description to be provided. |
| SI | Indefinite An indefinite period. |
| W | Week Period of seven days. |
| WD | Working days Days when the partner company normally works. |
| WW | 5 day work week Monday through Friday. |
| Y | Year |
| ZZZ | Mutually defined Period as per agreement. |