The best way to summarize data from multiple tables based on a date (month) is to create a "Months" table, and depending on the details that you want it could be good to create a "Days" table.
I'll explain the "Days" table, as I think this will help you best. Then you can always roll up things to weeks/months/years summary reports.
(If you get stuck or have other questions, post back, because this is considered an advanced technique)
Create a "Days" table.
Create one field called "Date".
Set the 'Date' field as the Key field on the table.
Use excel to pre-load all the records you might need.
i.e. 01-01-2014 thru 01-01-2025
Then create a relationship between all of those tables and the "Days" table.
Each Day will have many Time/Exp/Materials/etc.
Once the reference field is made on the child tables, it should be a 'Reference Date' field.
Then you can change that field properties to be a 'Formula - Date' field.
Then insert a formula that references the [Expense Date] field.
Now you will have a 'formula relationship' that will automatically connect all those records to the respective dates.
Create all the summaries you need. i.e. Total Amount - Time, Total Amount - Expense, etc.
