Hi Sam
The code is checking the dates and inputting the milestone in the correct week/date. For the gaps in between it adds in a number so working through the sheet if the date matches one of the dates in the ref cells it enters the specified milestone , if it doesn't it checks for the maximum number in the row and adds 1. So the furthest milestone will have the lowest value.
These numbers are then used to colour code in the macro "worksheet activate" using case statements