Time Synchronization with White Rabbit - Experience from Tunka-HiSCORE

Upcoming Gamma-Ray and Cosmic-Ray experiments require relative time calibration of all detector components with (sub-)nanosecond precision. White Rabbit, a new technology for time and frequency transfer, can be applied here. We describe a White Rabbit (WR) based design for trigger time-stamping, originally developed for Tunka-HiSCORE a timing array for Gamma-Ray astronomy now under construction. Subnsec synchronization results from cosmic ray shower data, in-situ artifical light source calibrations and laboratory tests taken over several years are presented.