Data format

a: A format of line -- start time, tab, end time, tab, a comment,
and a line feed mark -- an event.
Sample:
2013-08-12 13:30:00\t2013-08-12 14:00:00\tComment1\n
2013-10-07 07:30:00\t2013-10-07 08:00:00\tComment2\n
*\t is tab and \n is line feed mark.
b: The start time of an event must be before the end time.
c: The unit of time is the minute. If the event length is 1 hour and
the start time is 0 minute, the end time is 59 minutes.
d: The form of start time and end time is yyyy-MM-dd HH:mm:ss.
It has an space character between the date and time.
The seconds portion is 00.
e: The data format is a tab-delimited text.
f: If the line feed mark is \n by Mac, it will become \r\n by Windows.
g: In ManyTime app, it is usually set to \n. It will be changed into \r\n
if the end of line for Windows in the setting screen is turned ON.
h: Events in the file is sorted in ascending order by the start time.