Horology, determination and standardization of time, apparent and mean time, equation of time.
| Acronym | Sense | Language | Topics |
|---|---|---|---|
| AST | Atlantic Standard Time | In English | |
| BP | Before Present | In English | → Prehistory → History |
| CCW | Counterclockwise | In English | |
| DOA | Date of Announcement | In English | |
| DOP | Date of Publication | In English | |
| DOR | Date of Ratification | In English | |
| DOW | Date of Withdrawal | In English | |
| PM | Post Meridiem | In Latin | |
| RAG | Reusable Agenda | In English | |
| RTC | Real-Time Clock | In English | → Computer science |
| UT | Universal Time | In English |