Hi trish1120,
"RICHARD Tank birth: 9 November 1865, 0544, DUBLIN, DUBLIN, IRELAND
Parents RICHARD Tank and Mary LAWRENCE"
This must be correct as it is an actual birth record.
I suspect the date we have of January 01, 1866 was arbitrarily picked due to the time. The actual date of birth may have been forgotten by whoever was keeping records when moving from Ireland to Jersey to Canada. They probably picked Jan 01, 1866 arbitrarily knowing only that Richard Tank was born around the end of 1865.