1] Some data put in "Weekly Summary" sheet A11:H13 for testing purpose
2] In "Monthly Summary" sheet D7, formula copied across and down :
=IF($A7="","",IF((D$5>='Weekly Summary '!$B$5)*(D$5<='Weekly Summary '!$B$6),IFERROR(1/(1/VLOOKUP($A7,'Weekly Summary '!$A$11:$H$300,MATCH(INDEX($4:$4,MATCH("zz",$A$4:D$4)),'Weekly Summary '!$A$10:$H$10,0),0)),""),""))
Regards
Bosco