1   =MAX(MIN(H$17,$F18)-MAX(H$16,$E18)+1,0)
2   =OFFSET($I$9,30-ROW(),9-COLUMN())    //based off of /u/proof_by_excercise8, thanks!
3   =SUM(--(E20:S59^2>100)) CSE
4   =IF(EOMONTH($E19,$F19*12*G19)<=H$17,G19+1,G19)