Is there a way to have a single field act as a date/time field on a form? In the interest of having less field, I would refer to use only one field, rather than a time and date field to capture the same info?
What kind of data are you storing in the datetme? Is the lead actually going to be able to choose from any date @ any time?
There isn't currently a way to allow a lead to enter a date and a time in the same field.
Do you need them to be able to choose any date and any time? Or is it a list of events on specific days at specific times?
If that's the case then you could use a string field and make each of the Date/Time options in a picklist.