Description - Have visible arrows to let users know they have the ability to use up/down arrows to change time in the calendar. Why is this feature important to you - How else would users know they can use the keyboard up/down arrows?How would you like the feature to work -
The better option is to have those arrows visible and/or a tooltip to use them along with keyboard keys.
Current Behaviour - No indication is present that arrows can be used. Should be like AM/PM, if at all possible.