hey xld...
now i know where the mistake was...
like i sad in excel is by default that WEEKDAY() starts counting from sunday...so sunday is for them the 1st day in the week...but it actually should be the last or the 7th day in the week
thats why in this formula your wrote =ROUNDDOWN((DAY(H7)+WEEKDAY(H7-DAY(H7)+1)+5)/7;0) it made problems becouse it counted sunday for as it was new week so week+1 ... but thats WRONG...
so i had to make just a little change(delete) in that formula and now it wroks PERFECT i also checked it by myself changing manualy the dates...
so the formula should look like this if you what that the week starts also when monday starts:
=ROUNDDOWN((DAY(H7)+WEEKDAY(H7-DAY(H7)+1)+5)/7;0)
delete the red printed +1 and it works great...
=ROUNDDOWN((DAY(H7)+WEEKDAY(H7-DAY(H7))+5)/7;0)
so thanks again ... actually without you i couldn't make this =)