Date plus 1 and minus 1

[Knightwing]

@jsmith88 I manage to do the shorten version of your question.

[GUIDE] How to subtract one and add one to date

Here is one of many ways to substract one, add one to any date. Which caters to leap yrs and month last days Formula to -1 to date (([DAY_1_31])-1==0? ((([DAY_1_31]-1)==0)*((([MON]-1)==0)*31))+((([DAY_1_31]-1)==0)*((([MON]-1)==1)*31))+((([YEAR]%4)==0? (([DAY_1_31]-1)==0)*((([MON]-1)==2)*29):((([DAY_1_31]-1)==0)*((([MON]-1)==2)*28))))+((([DAY_1_31]-1)==0)*((([MON]-1)==3)*31))+((([DAY_1_31]-1)==0)*((([MON]-1)==4)*30))+((([DAY_1_31]-1)==0)*((([MON]-1)==5)*31))+((([DAY_1_31]-1)==0)*((([MON]-1)==6…