While developing an application having backend in PHP ,when I tried to go past the year 2037 the system jumped back to 1970!
This is a known bug in PHP and is a limitation in counter that is 32 bits long,64bit machines are not vulnerable to this.
As per forum
The last date/time that is working:
19.01.2038 03:14:07 ( =2147480047 )
The workaround for this issue is to have 64 bit machine/OS, if you are running any unix based machines. Also make sure that the time_t is set to 64bit !
Hope this helps... and save your time.