These docs are for an old release. Info on upgrading to v4
edit doc

hiddenDays

Exclude certain days-of-the-week from being displayed.

Array, default: []

The value is an array of day-of-week indices to hide. Each index is zero-base (Sunday=0) and ranges from 0-6. Example:

hiddenDays: [ 2, 4 ] // hide Tuesdays and Thursdays

hiddenDays: [ 1, 3, 5 ] // hide Mondays, Wednesdays, and Fridays

By default, no days are hidden, unless weekends is set to false.