There are different ways to use this date data. For example, if your date is x implies it is the distance from the 1st of the month. Similarly, it is some distance y months from the first of the year (January).
The day also matters. If the day is Friday => it's 5 days from the week start. You can include this as a different feature.
KSP is another way of reducing the date into a useful feature. Year +(#ofdays from the start of the year -0.5) /#ofdays in the year(356 or 355) leap year or not a leap year.
Hope this is useful.