how to set timezone default to america/los_angeles

[Freepls]

i know u can change it with php for a page by page basis, but i also know u can change it in the ini file(set the default timezone)
but well i dont know how to do the ini file and im not sure if its allowed on freehosting but well..
can someone let me know if its allowed? or
how to make it so that whoever is viewing my site (the time is in their timezone for them)
sees the right time it is there.
I use Free hosting at http://myplus.org