# UK Fajr and Isha Observations

## Hizbul Ulama UK — Blackburn (1987-1989)

**Location:** Rural outskirts of Blackburn, Lancashire (53.748°N, 2.48°W, ~120m)
**Source:** http://www.hizbululama.org.uk/files/salat_timing.html

A systematic observation program conducted over two years with 21 successful Fajr sightings
and corresponding Isha (Shafaq al-Abyad) records. Observations were made from a dark rural
site in northwest England.

At 53.7°N, this is among the highest-latitude systematic Fajr studies on record. Key findings:

- Summer solstice observations are particularly important — at 54°N in June, true dawn appears
  at a very early local time and the sun's arc through the horizon zone is extremely shallow
- Winter Fajr requires very long darkness periods to observe
- Shafaq al-Abyad (Isha) does not fully disappear in summer at this latitude — a controversial
  finding with significant fiqh implications

The 21 observations are spread across all seasons. Times are published to the nearest minute
in the Hizbul Ulama account.

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## Asim Yusuf — "Shedding Light on the Dawn" (2013-2016)

**Location:** Exmoor National Park (51.15°N, 3.65°W, ~430m); Exmoor is an International Dark
Sky Reserve — one of the darkest locations in southern England.
**Source:** ISBN 978-0-9934979-1-9 (2017)

This is the most scholarly treatment of the UK Fajr controversy. Asim Yusuf conducted 18
multi-observer sighting sessions at three dark-sky UK sites between 2013 and 2016, covering
all four seasons at each site. His methodology:

- Multiple independent observers present simultaneously
- Detailed photographic documentation
- Explicit recording of "awwal al-tulu'" (first detectable light) vs "Fajr Sadiq" (true dawn)
- Elevation correction (Exmoor at 430m is significantly above the surrounding valley)

**Key results:** Consistent findings of true dawn at 12°-14° depression at Exmoor. The summer
solstice observation is critical — at 51°N in June, the sun barely reaches 15° below the
horizon, making the summer Fajr time very late (after midnight local time).

The Exmoor site at 430m is relevant to the elevation variable: being significantly elevated
above the surrounding valley and atmosphere extends the observability of twilight phenomena.

**Isha findings:** Shafaq al-Abyad (white twilight) disappearance observed at 15°-17° depression
in winter and autumn, with later times in summer (longer twilight persistence at 51°N).

### Fiqh Implications

Both the Blackburn and Exmoor studies raise challenging questions for high-latitude UK communities:
- The 18° convention places Fajr unrealistically early in summer (before astronomical midnight)
- The observed 12°-14° is more consistent with what the human eye actually perceives as dawn
- Yusuf's work contributed to the ongoing academic discussion about whether high-latitude
  communities should use a different calculation method

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## Impact on pray-calc

These UK observations at 51°N-54°N are critical anchor points for the latitude variable in
the ML model. They demonstrate that depression angle varies with latitude (52°N Birmingham
at ~13°, versus tropical sites at ~16°-18°) and suggest a latitude-dependent correction term
may be needed in any generalized algorithm.