day

This defines a day dependency for a current node. The parameters are the names of weekdays (lowercase): sunday, monday, tuesday, wednesday, thursday, friday or saturday. Any combination is acceptable. Names must be typed in full and at least one must be given. Giving the same weekday more than once is not treated as an error. The names can be shortened as long as there is no ambiguity.
There can be multiple day dependencies, but it is more convenient to define just one dependency, listing the weekdays the node is to run.
Combined with a date, you can specify more particular dependencies such as the first Monday in a month:

task x
   date 1-7.*.*    # This will not work
   day monday

Will be listed by the show as

task x
   date 1.*.*
   date 2.*.*
   ...
   date 7.*.*
   day monday

Since the number of days in a month varies, there is no direct means to specify, say, every last Sunday of each month. A list of dates must be provided.
If a hybrid clock is defined, any node held by a day dependency will be set to complete at the beginning of the suite, without the node ever being despatched. Otherwise the suite would never complete