The Astronomical New Moon is on Tuesday 26 November 2019 at 3.06 pm. The crescent cannot be seen on this day.
The calculations for crescent visibility on Wednesday 27 November 2019 for London is as follows
Sunset 4pm
Moonset 4.52 pm
Crescent leg time 52 minutes
Crescent age 24 hours 55 minutes
Crescent altitude 5.50 degrees
Crescent elongation 13.26 degrees
The crescent is visible with optical aid only and therefore Thursday 28th November 2019 will be the completion of the lunar month, 30th Rabi ul Awwal
1st Rabi ul Akher 1441AH is expected to be on Friday 29 November 2019 in Europe