The default time unit for new TaskMaps is minutes. Consequently, when you drop new Task or Task Link shapes onto a drawing page, the Time Units field will be set to minutes.
You can change the default time units for a TaskMap by clicking the TaskMap Options button on the TaskMap toolbar. This button also allows you to change the abbreviations used for the five time units.
If you would like to change default time units or time abbreviations for TaskMaps that you create in the future, you can make the desired changes and save the TaskMap as a template, often along with changes you’ve made to customize the role list or by adding background pages containing style elements.