Adding a single date and number to a max list of 20

I'm looking to input only a single date and number and have that information automatically update a list of 20 (dropping off the oldest entry).

I know the below coding will bring in the last 20 entries of a list:

=IF(ROWS($AC$95:$AC95)>MATCH(REPT("Z",255),$C$4:$C$2902),"",INDEX($C$4:$C$2902,MATCH(REPT("Z",255),$C$4:$C$2902)-MIN(20,MATCH(REPT("Z",255),$C$4:$C$2902))+ROWS($AC$95:$AC95)))

Is it possible to record a single date and number in Columns A1 & B1, then in Columns F & G update automatically to a max amount of 20 entries?

See sample, I marked in yellow the last entry.