---
title: "Acclimatised — EASA Definition · Avioverse"
description: "ORO.FTL.105, Regulation (EU) No 965/2012: ‘acclimatised’ means a state in which a crew member’s circadian biological clock is synchronised to the time…"
url: "https://avioverse.aero/glossary/easa/acclimatised"
---

# acclimatised

EASA defines “acclimatised” in one regulation. The wording below is reproduced verbatim from the EASA Easy Access Rules, with a link to the paragraph it comes from.

> ‘acclimatised’ means a state in which a crew member’s circadian biological clock is synchronised to the time zone where the crew member is. A crew member is considered to be acclimatised to a 2-hour wide time zone surrounding the local time at the point of departure. When the local time at the place where a duty commences differs by more than 2 hours from the local time at the place where the next duty starts, the crew member, for the calculation of the maximum daily flight duty period, is considered to be acclimatised in accordance with the values in the Table 1.
>
> \[The definition continues with a table — see the regulation.]

ORO.FTL.105 · Air Operations · Regulation (EU) No 965/2012 · Easy Access Rules, 27 Mar 2026 revision · [Read ORO.FTL.105](https://avioverse.aero/regulations/easa/air-ops/part-oro/subpart-ftl#oro-ftl-105)

## Defined in the same article

- [accommodation](https://avioverse.aero/glossary/easa/accommodation)
- [airport standby](https://avioverse.aero/glossary/easa/airport-standby)
- [augmented flight crew](https://avioverse.aero/glossary/easa/augmented-flight-crew)
- [break](https://avioverse.aero/glossary/easa/break)
- [delayed reporting](https://avioverse.aero/glossary/easa/delayed-reporting)
- [disruptive schedule](https://avioverse.aero/glossary/easa/disruptive-schedule)
- [duty](https://avioverse.aero/glossary/easa/duty)
- [duty period](https://avioverse.aero/glossary/easa/duty-period)