The Vertical Override mini-calendar modifier specifies, for a given mini-calendar, that the flow of dates should be from vertical, even though it is set to false in the flow of dates mini-calendar options.
The vertical override modifier is
:vrt

The vertical override modifier is useful when mixing vertical and horizontal mini-calendars on the same page.
See also: Horizontal Override and other mini-calendar modifiers.
Topic 176180, last updated on 23-Jun-2020