| Abbreviation | Definition |
|---|---|
| a.m. | ante meridiem - morning, before noon |
| AANE | Add A New Entry |
| ACDT | Australian Central Daylight Time |
| ACE | After Christian Era |
| ACST | Australian Central Standard Time |
| ACST | Australian Central Standard Time [Coordinated Universal Time (UTC) + 0930] |
| ACT | Australian Central Time |
| ADT | Arabia Daylight Time |
| ADT | Atlantic Daylight Time |
| AEDST | Australian Eastern Daylight Saving Time |
| AEDST | Australian Eastern Daylight Savings Time |
| AEST | Australian Eastern Standard Time [UTC + 1000] |
| AET | Australian Eastern Time |
| AFT | Afghanistan Time |
| AKDT | Afghanistan Time |
| AKDT | Alaska Daylight Saving Time [UTC - 0900] |
| AKST | Alaska Standard Time [UTC - 1000] |
| AKT | Alaska (AK) Time |
| ALMT | Alma-Ata Time |
| AM | Ante Meridian |