Within this context TimeTicks are UNIX timestamps.
Unix time, or POSIX time, is a system for describing points in time: it is the number of seconds elapsed since midnight UTC of January 1, 1970, not counting leap seconds. It is widely used not only on Unix-like operating systems but also in many other computing systems.
ActionScript_TimeConversions_Example
Click here to download a simple example model shows that different possibilities for DateTime conversions with Scheer PAS Designer.