In linux, date can help me to print the current time. If want to print the current time + 1 hour, what option should I give?
Just use -d (or --date) to do some math with the dates:
date -d '+1 hour' '+%F %T'
# ^^^^^^^^^^^^
For example:
$ date '+%F %T'
2013-04-22 10:57:24
$ date -d '+1 hour' '+%F %T'
2013-04-22 11:57:24
# ^
Warning, the above only works on Linux, not on Mac OS.
On Mac OS, the equivalent command is
date -v+1H