This is to provide a compact format of periods from a start time to an end time.
For example, for English
from Jan 10, 2008 to Jan 20, 2008, the compact format is Jan 10-20, 2008
from Jan 10, 2008 to Feb 10, 2008, the compact format is Jan 10 - Feb 10, 2008
from Jan 10, 2007 to Jan 10, 2008, the compact format is Jan 10, 2007 - Jan 10, 2008
from 10:10am to 11:10am, the compact format is 10:10-11:10am