How is Dataflash logs filenames date determinate?

I’m an IRIS owner with APM Copter 3.2RC2 and i do use APM Planner 2.0
How are Dataflash logs filenames date determinate ?

I do currently have data flash logs dated in January 1970
70-01-17_06-54-58.bin (unix time stamp == 0 + a few seconds)

How can i fix it ?
Is this issue related to APM Planner or to APM Copter ?

I ve compiled the last version of APM Planner 2.
And the issue is now fixed.