High-frequency data can include seasonal factors that affect economic activity. The timing of federal and local holidays changes each year, and weekends can fall all over the place in any given month. So not every period has the same number of business days. FRED now has data to help you sort that out.

Although it doesn’t account for holidays, the graph above shows the number of weekdays in a month. The data come from a release on domestic auto and truck production from the Board of Governors, which helps in cleaning the data of seasonal and predictable factors. The variation in weekdays is actually quite important, as it fluctuates between 20 and 23 days per month, which is a difference of over 10%.

The second graph shows the number of weekdays in a quarter, which fluctuates between 64 and 66 days, a difference of  about 3%, which is still large when you consider the typical quarterly growth rate of an economy is between 0.5% and 1%. The last graph shows the same statistic for a full year, between 260 and 262 days. Here, the difference is less than a percent, but it’s still significant.

How these graphs were created: For the first graph, search for “weekday” and the series we use here should be at the top of the list. Do the same for the second and third graphs, but use the “Edit Graph” panel to change (1) the frequency to quarterly and annual, respectively, and (2) the aggregation method to “Sum.”

Suggested by Christian Zimmermann.