Prove Einstein's ideas

Max Born
Examine the relativistic ideas: Two space ships crossing You have two battle ships running across each other. Light waves (x=ct) are used to synchronize the time duration. Each ship sets the duration according to its velocity (no delay between the ships). Note that the t++- and t--buttons produce different results by color. Just prove the consequences of when the unity of time is missing.
Check to coincidence of the waves (grey) with the edges of the ships and read the time (variable t) The time duration on each ship is recorded during the crossing of one wave length.