FIND A DAY
Find on what day a date occurred (or will occur)
from 1st January, the year 1000 A.D. onwards.
Select the Month and Day from the drop-down lists,
delete 'Year' & key-in a year with value 1000 or higher.
Click Return.. to obtain the day of the week; and more !!
NOTES on the BRITISH CALENDAR BEFORE 1753
...which this routine acts on, subject to the following:-

PLEASE NOTE that before 1753, the British year started on March 25th, NOT January 1st.
If you enter a year pre-1753 (with date Jan 1st-25th March), enter the year as it would become on the subsequent March 25th.
(i.e. pretend that the year started 1st January)
ALSO, in 1752 the dates September 3rd to 13th were dropped from that year's calendar in order
to correct the calendar from its accumulated errors.