Seems like a small thing, but it's a wast of time and very frustrating, so I'm wondering if I'm just doing this incorrectly

Using the change calendar as an example, how do I schedule a start time in the future without repeatedly opening and closing the calendar or getting multiple prompts that my date is impossible?

Also, how do I clear a date/time if it was put in there accidentally?

If I assume this is how it works,

• If time is intended to be selected first, can it be above the date?
• Can we have an OK button instead of picking a day closing the calendar?
• Given that we are forced to pick the time first (unless I'm wrong about that) in order to not close the calendar, can we wait for validation of the date to be done until after we've <clicked> on the date to close the calendar instead of when we change the time?
• Can we have the option to default to a time (say, top of the hour)?

Adam