Events that start or end in hidden areas are marked with *_event_continueleft and *_event_continueright classes.
This lets you display the events start/end with different styling to make it clear that the event continues in the hidden area.
Example from scheduler_white theme:
.scheduler_white_event_continueright .scheduler_white_event_inner {
border-top-right-radius: 0px;
border-bottom-right-radius: 0px;
border-right-style: dotted;
}
.scheduler_white_event_continueleft .scheduler_white_event_inner
{
border-top-left-radius: 0px;
border-bottom-left-radius: 0px;
border-left-style: dotted;
}