Documentation of statistics: The annual and quarterly working time accounts before the 2016 revision (Discontinued)
The current time series goes back to 2008 (quarterly statistics as from the 1st quarter of 2008).
https://www.dst.dk/en/Statistik/dokumentation/documentationofstatistics/the-annual-and-quarterly-working-time-accounts-before-the-2016-revision--discontinued-
Documentation of statistics