# fleet.tachograph-rest

Status: needs review by a drivers' hours / transport compliance expert before it is published.

Checks a driver's recorded activities for daily and weekly rest under
Article 8 of Regulation (EC) No 561/2006, as it applies in Great Britain
(assimilated law). It counts the daily and weekly rests taken and returns
every breach in time order. Driving and break limits are checked by
`fleet.drivers-hours`, which takes exactly the same input and whose
`DriverActivity` and `HoursBreach` types this capability uses.

## Input

`startDate` and `startTime` are when the first activity starts, and **the
records must begin straight after a weekly rest**: that is when the first
24-hour daily rest window and the six-day weekly rest window open, and the
weekly rest before it is taken to be a regular one. Activities are back to
back; neighbouring rests are merged into one uninterrupted rest. Local
wall-clock time, no time zones.

## How rests are judged

- **Daily rest, Art. 8(2).** Within each 24 hours after the end of the
  previous daily or weekly rest, the driver must have taken a new daily rest.
  Only the part of a rest inside that 24-hour window counts: 11 hours or more
  inside it is a regular daily rest, 9 to 11 hours is reduced, so an 11-hour
  rest that starts 14 hours into the window is a reduced one. A rest of at
  least 3 hours earlier in the same window followed by one with 9 hours inside
  it is a split regular rest (Art. 4(g)); 9 then 3 is a reduced rest followed
  by a break. The next window opens when the qualifying rest ends. If no rest
  of 9 hours starts in the window, that is a `daily-rest` breach at the
  window's end, and checking picks up again after the next rest of 9 hours or
  more.
- **Reduced daily rests, Art. 8(4).** At most three between two weekly rests;
  the fourth and later are `reduced-daily-rest` breaches.
- **Weekly rest, Art. 8(6).** Any rest of 24 hours or more is a weekly rest,
  regular at 45 hours or more, otherwise reduced. It must start no later than
  six 24-hour periods (144 hours) after the previous weekly rest ended, or it
  is `weekly-rest-late`. If the records run past that point with no weekly
  rest at all, the breach is reported at the deadline, unless the records end
  in a rest that began in time and may yet become one.
- **Two reduced weekly rests in a row** are a `reduced-weekly-rest` breach.
  This is a simplification of Art. 8(6) ("in any two consecutive weeks ... two
  regular weekly rest periods, or one regular and one reduced").

| rule | `actual` | `limit` |
|------|----------|---------|
| `daily-rest` | longest rest inside the window, minutes | 540 |
| `reduced-daily-rest` | reduced daily rests since the last weekly rest | 3 |
| `weekly-rest-late` | minutes from the previous weekly rest to the next one (or to the end of the records) | 8640 |
| `reduced-weekly-rest` | length of the second reduced weekly rest, minutes | 2700 |

A rest cut off by the end of the records is judged at the length recorded.

## What it does not do

- Compensation for a reduced weekly rest (Art. 8(6), 8(7)): the lost hours
  must be made up, attached to another rest of 9 hours or more, before the end
  of the third week. Not checked.
- The 2020 amendments for international goods drivers (two consecutive
  reduced weekly rests outside the member state, four-week pattern; return
  home every four weeks; no regular weekly rest in the cab). Not checked.
- Multi-manning (9 hours within 30), ferry and train interruptions (Art. 9),
  the 12-day derogation for occasional passenger services, and the
  exemptions and national derogations.
- GB domestic rules (Transport Act 1968) and AETR.

## Data

The limits are dated rows in `data/rest-limits.json`, effective from 11 April
2007 (Art. 29) and still in force. A date before that is an error.

## Sources

- Regulation (EC) No 561/2006, as it applies in the UK, legislation.gov.uk:
  Article 4(g) and (h) (regular, reduced and split daily rest; regular and
  reduced weekly rest), Article 8(2) (a new daily rest within each 24 hours;
  the portion inside the 24 hours decides whether it is reduced), 8(4) (at
  most three reduced daily rests between two weekly rests), 8(6) (two
  consecutive weeks; weekly rest to start within six 24-hour periods).
  https://www.legislation.gov.uk/eur/2006/561/article/8 and
  https://www.legislation.gov.uk/eur/2006/561/article/4
- DVSA, "Drivers' hours: Assimilated rules" (11 hours, reducible to 9 three
  times between weekly rests; 45 hours weekly, reducible to 24 every other
  week; weekly rest after six consecutive 24-hour periods):
  https://www.gov.uk/drivers-hours/eu-rules
- DVSA, "Drivers' hours and tachographs: goods vehicles", section 1.5 (the
  24-hour period runs from the end of the previous rest; split rest 3 hours
  then 9): https://www.gov.uk/guidance/drivers-hours-goods-vehicles/1-eu-and-aetr-rules-on-drivers-hours

1.0.1 fixes Python accepting a trailing newline or non-ASCII digits in startDate and startTime; adds tests.

## Before you rely on this

**Not professional advice.** This capability calculates drivers’ hours figures from published rules. It is a software component for developers, not legal advice. Rules change and every rate here has an effective date. Check that the dates cover your case. Verify results against the official sources listed above, and have a transport compliance specialist review how you use it, before anyone relies on the output. Provided "as is" under its licence, without warranty.

**Unreviewed.** This capability's implementations agree in every language and pass its published test vectors, which were worked out from the official sources cited. But no qualified transport compliance specialist has yet checked those vectors, or confirmed that the capability covers the cases it claims. Treat it as a draft. Do not use it for real people, money or decisions without your own expert review. Once a qualified reviewer signs off, this notice is replaced with their name, qualification and the date. Each new version needs fresh sign-off.

## Notices

Contains public sector information licensed under the Open Government
Licence v3.0 (https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/).

Legislation: Crown copyright and database right.

1.0.2 marks it unreviewed and adds its attribution notices (NOTICE). The code and the tests are unchanged.