Yep, if you want to go forward in time on the Schedule tab, use your “right” arrow. If you want to go back in time, use your “left” arrow. If you’re on the week or weekday view, you’ll move to the next week, and if you’re on the day view, you’ll move to the next day.
So no need to point your cursor at the small arrows above the calendar, which is especially handy when you want to arrow forward or backward many weeks.
If you love shortcuts, you might also check out this blog post about a quick method for entering a new client right on the Schedule tab.