All the classes will be prefixed with the value of CssClassPrefix property.
Example:
CssClassPrefix="month_green"
"_message" will result in "month_green_message".
_message
Message bar.
_message_close
Close icon of the message bar.
_event
Main event box.
_event_inner
A <div> inside event box (_event).
_event_hover
Added to the main event box when the cursor is on an event (in addition to _event).
_selected
A selected event (in addition to _event).
_event_continueleft
Events that start outside of the visible area.
_event_continueright
Events that end outside of the visible area.
_shadow
Moving/resizing shadow marker.
_shadow_inner
A <div> inside _shadow.
_main
The topmost <div>.
_header
Day header (Monday, Tuesday...) cell.
_header_inner
A <div> inside _header.
_cell
Day cell.
_cell_inner
A <div> inside _cell.
_previous
A day cell in previous month (in addition to _cell).
_next
A day cell in next month (in addition to _cell).
_cell_header
Day cell header (with day number).
_cell_business
Business time cells (defined as Monday - Friday). Used in addition to _cell.