Allow date/time fields to not be auto-filled with current date/time

The date field does not default to current, just empty. The date/time field however presets to the current date/time, which can be annoying (esp when you are trying to change times). This function now allows an option to not preset to current date/time. It defaults to true for backward compatibility.
does this work for those guys whose clock has 24 hours an no am/pm?