problem with cron jobs time for whmcs

hello i'm install whmcs 7.4.1 but after install, problem whit cron job time example : my server linux time is 16:00 my site time is 16:00 timezone and date on cpanel and centos is Perfect Correct but cron job time on whmcs is 12:00 And instead of at 00:00, tomorrow's invoices will be issued at 4:00 AM! example : date and time on admin my whmcs is : Tuesday, 23 January 2018, 16:12 but time cron : Cron Status Ok Last Run: 2018/01/23 12:40 The linux & whmcs clock is set and true, and only Crawl Jobs is 4 hours behind How do I match the cron clock with the site and server clock? please help me thanks ...