Minimum period to begin journey after visa stamping

[SCD_Path2Usa]

Hi,
I want to know if there is any minimum limit in which you have to travel to USA after the visitors visa is stamped? For instance, if my in-laws get their visa stamped in Feb and wish to travel in Dec, is it allowed?
Thanks.

[want2go2us]

Even I wanted this information. But what feedback I got is, this is 10 yr multiple visa and the applicant can go to US before expiration of that visa. Others may want to add to this....

[ps2005]

They can travel anytime before the Visa Expires...........