When you select Options > Month to date only the transactions from the prior month up to the same day of the current month are included. So for example, if today is the 7th of the month, the current month would only include transactions from 1st to 6th of the month and so only the transactions from 1st-6th of the comparison month would be included. This only has an effect in summary view, variance mode and stream mode and only when the displayed periods include the current physical month. For example, if the actual date is the 15-Nov-2014, activating 'month to date' will only have an effect if November 2014 is being displayed.
In summary view both the current and previous periods need to include the same month for each respective year. For example, if the actual date is the 15-Nov-2014, 'month to date' will only work if both the current and previous periods include November.
Month to date only has an effect if the end month of the current period is the current month and current year.
Administrators may set some databases to turn on the Month to date option by default.
Month to date example
Impact on performance
The 'Month to date' option can have a major impact on performance, especially on large databases. While it can be used effectively on general queries, extreme caution should be used when using this option on a collection of dashboard widgets, as the compound impact on performance can be severe.