From the source code, it appears that the value is ignored if it is set to 0. If that does not work, set it to a very large number. The value is an integer that represents seconds, so setting it to 31536000 equates to about a year. Setting it to 2 billion equates to over 63 years.
Oops, misread the code. It cannot be 0. Use a large number.
Thanks for your information. I will try it out. For the time being I used 24Hour(86400) as the value.