Allows you to manipulate time in most (even 3rd party) programs on Linux.
time(2) and clock_gettime(2) are usually located in shared libraries, so if your application isn't statically linked, then this work with the program.
Tested on Debian.
To compile gcc -fPIC -shared -o libtimemachine.so timemachine.c -ldl
To use
SECONDS_OFFSET=14123 LD_PRELOAD=pwd/libtimemachine.so date