One of the easiest ways to create an MTD value is to express time as a percentage.
Take a look at the following table:
Starting with the 1st day of the month add all twelve months. Next subtract each month from the 1st day of the month and divide by the range of 365 to express time as a percentage.
Now multiply any value that you want to see as month-to-date value by the percentage starting in month 2 going forward.
To express time as a year-to-date value simply add every day of the year to your table: