Thank you friends for your nice comments, there is a bug in the dateTimeDiff() function. i got that function from the internet, but there is a bug in that function. so i wrote a new function for that and uploaded a new version of the plugin.
you just need to unistall the previous plugin and install the new version of the plugin.
In New Version
1. Fixed bug in the dateTimeDiff()
2. the plugin now support unicode for any langugage, (characters are encoded)
Thanks for your comments and karma