Looking at the past few years of observation data, it appears that (1) it is possible to sight the first day’s Hilal on the UK horizon throughout the year (if a real effort is made), (2) attempting to sight the Hilal on 29th day (of Morocco) and the next day, shows that UK-only criteria will triple the number of 29th days sighting, InshaAllah (see tables below). [charts] [View Observation Results] [UK Moon Sighting Fatawa]

Comparison UK Morocco1443a
Comparison UK Morocco1444a
Comparison UK Morocco1440a
Comparison UK Morocco1439a
Comparison UK Morocco1439a
Comparison UK Morocco1440a
   

Note: a lunar calendar is self-correcting and does not accumulate errors. For example, if a 29th-day sighting was missed (eg. 3/3/2022), leading to completing 30-days, then the following month's 30th (eg. 2/4/2022) will become 29th, without affecting the subsequent months!