I have an issue with pivot tables, previously my pivot table contained months
where each month was written like "January, February" etc, but now I have
changed the way the months are written to "01-january, 02-february". My
problem is that even though the data with the old month names no longer
exists in the pivot table, the pivot table still provides "January, February"
etc. as filtering options in the month category. I've tried updating the
pivot table but it doesnt help. The only way i've been able to get rid of
this was by creating a new pivot table.

Now I have an issue with changing the names of people assigned to different
functions, as people join and leave the company I am annoyed that all of the
old employees are still listed in my filters, how can I fix this issue
without having to create a new pivot table every time?