Agreed! One work-around that can work for the 'month filter', is to add a formula field with the formula:
IF({your date field name here},
DATETIME_FORMAT({your date field name here}, 'MMMM'))
Where 'your date field name here' is your date field (of your expenses or invoices) you want to convert to a month. You can then add a filter to filter on 'contains' or 'is' October for example.
Duplicate the formula field and change the forumla from 'mmmm' at the end to 'yyyy' and it will display the year from your date field. Then you can run a filter on that field too.
Bit of a schlep and not as easy as just having the options in the filters, but if you want the functionality, then you can set it up - which is what I am doing just now with one of tables, filtering on the Month.
wondering if I can take this a step further and filter by weeks - maybe somehow naming the weeks 1-52?