Glossary:Working-day adjustment

From Statistics Explained

Working-day adjustment is a statistical method for removing the calendar effect from an economic time series. The calendar effect is the variation caused by the changing number of working days in different months or other time periods (quarters, years).

Working day adjustment is mainly used in the calculation of short-term statistics (STS), for converting gross figures or indices into their working-day adjusted equivalent. In order to adjust a figure or an index, the calendar nature of a given month is taken into account and calendar effects are removed, whatever their nature. The number of working days for a given month may depend on:

• the timing of certain public holidays (Easter can fall in March or in April, depending on the year);
• the possible overlap of certain public holidays and non-working days (1 May can fall on a Sunday);
• the occurrence of a leap year.

Related concepts

• Seasonal adjustment
• Trend cycle