Populating projected data based on date and frequency

I often build a 52 week projection to manage weekly maintenance work load. It is a complex spreadsheet made worse by my inability to populate the fields automatically based on the raw data. See attached dummy. Task 1 row shows what the output for a weekly task would look like, as does task 2 for a 2 weekly task. Note the dates fall into the period between the start of one week and the start of the next. ie. falling on different days within any given week.

The sheet is made up of 52 weeks with dates in columns and maintenance tasks shown in rows.
Each task is plotted across the 52 weeks based on the last done date and frequency in days. Where the week and the due date match the filed is populated with the estimated duration. The problem is that the dates must project into the future and into the past between week 1 and week 52.
While I can get the matching fields to populate the preceding and subsequent fields remain blank. I'm unsure if the solution's is macro based or formula based. But any suggestions as to how to automate the population of this spread sheet would be greatly appreciated.
Thanks
Peter