Every report has a Reference date: the "as of" date its data is taken from, counted from the day the report is sent. For example, a report sent on a Monday with the reference date Yesterday shows Sunday's data. With End of last month, it shows the last day of the previous month.

The options are Today, Yesterday, End of last week, End of last month, End of last quarter, End of last year, and the "End of current" versions of week, month, quarter and year.

[Image: The report form's "Reference date" field with its options]

Each delivery shows Data as of that date, so recipients know which day they're looking at.