To calculate the time difference, we subtract the UTC offset of Buffalo, NY from the UTC offset of London:
UTC-05:00 - UTC+01:00 = UTC-06:00
This means that Buffalo, NY is 6 hours behind London.
Therefore, if it is 10 AM in London, the time in Buffalo, NY would be:
10 AM - 6 hours = 4 AM
So, when it is 10 AM in London, it is 4 AM in Buffalo, NY.