MapMatching - time should be start from 0 or can also be since UNIX epoch (January 1, 1970 00:00:00 UTC)?

MapMatching - time should be start from 0 or can also be since UNIX epoch (January 1, 1970 00:00:00 UTC)?

from zero
new GPXEntry(lat, long, 0)
new GPXEntry(lat, long, 2000)

from UNIX epoch
new GPXEntry(lat, long, 1543570343000)
new GPXEntry(lat, long, 1543570345000)