The timestamp you're using, 1184616000, is the time in seconds since Jan. 1, 1970 in YOUR time zone, which is 4 HOURS AHEAD of Greenwich time (GMT).
Fumigator was saying that you were getting different dates with that timestamp because the servers were using different time zones. If you use the gmdate() function, all the servers will report back with GMT time. If you use date(), they'll report back with their own timezones. So what you're really looking for is every server to report back with YOUR time zone.
Try using the date_default_timezone_set
to set the default timezone before running your date scripts.