Are you already using the Holiday Calendar feature in MS Project? If you aren’t or you want to learn more about how to make your schedule more accurate, keep reading! The default “holiday calendar” in MS Project is called “Standard” (see Fig 1), and actually has no holidays in it (see Fig 2). If it did, it would look like Fig 3.

Figure 1: Default Project Creation

Figure 2: Default “Standard” Calendar

Figure 3: Example Holiday Calendar Entries

The official list of US Federal Holidays is provided here: Federal Holidays (opm.gov). There are 11, including the recent addition of Juneteenth. That’s more than two weeks’ worth of non-work days! If you aren’t using a holiday calendar in MS Project, your schedule could be off by two weeks at any given time. In addition to holidays, most staff take a day of vacation on the Friday after Thanksgiving, as well as take time off during the period between Christmas Day and New Year’s Day.

Given all this, the holiday calendar is error-prone and a pain to construct. Some holidays have a fixed-date which requires re-jiggering for the preceding Friday or succeeding Monday when such a holiday falls on a weekend. Other holidays have fixed days such as “the fourth Thursday in November.” This requires determining the actual date each year. There are 340 such calendar entries in the years spanning 2020-2050.

I’m a passionate believer in the holiday calendar. Newly-retired and motivated by the recent addition of Juneteenth, I attacked the construction and I’ve now created a “strict” calendar version that includes only the official federal holidays, as well as a “realistic” calendar version that also includes the Friday after Thanksgiving and the entire period from Christmas Eve through New Year’s Day. I recommend using the latter—no one will criticize you for avoiding scheduling events during Christmas break. Note that a holiday calendar does not prevent staff from working—it just avoids scheduling on certain dates.

You can obtain a template file containing both calendar versions from the website MSProjectHolidayCalendars.com. There is a $10 fee. These calendars were auto-generated using custom code plus some manual editing, so they are quite reliable. I’d love to hear from you in the comments below if you try it.