README for Date-Span

This module provides code for dealing with datetime ranges that span multiple
calendar days. This is useful for computing, for example, the amount of seconds
spent performing a task on each day. Given the following table:

  event   | begun            | ended
 ---------+------------------+------------------
  loading | 2004-01-01 00:00 | 2004-01-01 12:45
  venting | 2004-01-01 12:45 | 2004-01-02 21:15
  running | 2004-01-02 21:15 | 2004-01-03 00:00

We may want to gather the following data:

  date       | event   | time spent
 ------------+---------+----------------
  2004-01-01 | loading | 12.75 hours
  2004-01-01 | venting | 11.25 hours
  2004-01-02 | venting | 21.25 hours
  2004-01-02 | running |  2.75 hours

Date::Span takes a data like the first and produces data more like the second.
(Details on exact interface in the POD.)
