есть готовый класс

DHTML Date/Time Selector
(c) dynarch.com 2002-2005 / Author: Mihai Bazon
For latest version visit: http://www.dynarch.com/projects/calendar/
Distributed under GNU LGPL. See http://gnu.org/licenses/lgpl.html for details.

Date selection:
- Use the «, » buttons to select year
- Use the ‹, › buttons to select month
- Hold mouse button on any of the above buttons for faster selection.

Time selection:
- Click on any of the time parts to increase it
- or Shift-click to decrease it
- or click and drag for faster selection.