Index and Match Formula to Capture Sums Inccured at Week Ending Intervals and show as a month

[wesselsV]

Hello,

I'm having an issue trying to run an index and match formula to capture costs incurred during a week, say 07-Jan-18 and then summarising these into "Jan-18". I've tried something similar with non-date data and I can get index and match to work but not with dates.

=INDEX('Budget'!$EI$49:$JC$60,1),MATCH($B2,'BUDGET'!$EI$47:$JC$47,1),MATCH($B3,'BUDGET'!$EI$48:$JC$48,1))

A file link is below:

https://1drv.ms/x/s!As-9OWf6QipWg0sKOuxpXANMUf8D

Thanks