If you mean the arrow ends of existing links, they can be hidden using CSS.
The arrows are marked with the following CSS classes:
scheduler_default_link_arrow_down
scheduler_default_link_arrow_up
scheduler_default_link_arrow_left
scheduler_default_link_arrow_right
You can hide them like this:
.scheduler_default_link_arrow_down,
.scheduler_default_link_arrow_up,
.scheduler_default_link_arrow_left,
.scheduler_default_link_arrow_right {
display: none;
}