Orijinal gönderinin sahibi: taylorbonish ,
When that message appears, go under disk utilities, click "terminal," and once that pops up, type "date" and hit enter. The date will probably appear as incorrect (mine was set at the year 2000). Type date again and then type in the correct date in the format MMDDHHYYYY (month, day, hour, year) and hit enter. Then try installing again. It worked for me!