The Astronomical New Moon is on Monday 20 July 2020 at 6:30pm. The crescent will not be visible on this day.
The calculations for crescent visibility on Tuesday 21 July 2020 for London are as follows:
Crescent age 26 hours 33 minutes
Crescent altitude 7.23 degrees
Crescent elongation 14.43 degrees
The crescent can be seen by an optical aid. It is unlikely to be seen with naked eye.
InshaAllah, 1st Zilhajj 1441AH is expected to be on Thursday 23 July 2020 in Europe.