Optional
If boolean and true and the unit is set to 'week', then the first day of the week will be Monday. Otherwise, it will be Sunday. If number, the index of the first day of the week (0 - Sunday, 6 - Saturday)
If defined, dates will be rounded to the start of this unit. See Time Units below for the allowed units.
The format string to use for the tooltip.
If defined, will force the unit to be a certain type. See Time Units section below for details.
If boolean and true and the unit is set to 'week', then the first day of the week will be Monday. Otherwise, it will be Sunday. If number, the index of the first day of the week (0 - Sunday, 6 - Saturday)