I was trying to talk about subjective perception of time, not time measurement. For example, one aspect of linear time perception is that completing a task before a deadline is the most important moment of that task. In a cyclical perception of time, the focus is more on doing it right and maintaining harmony, where the deadline is not a fixed but flexible target. Linear time perception's sole focus is on the passing of time, cyclical time perception will cheerfully ignore the passing of time if a good conversation isn't finished yet.
Another example that I love is the difference between "where" our past and our future is. Most westerners, when they visualize the future, it is in front of them - the space between us and the horizon as a virtual time line. In Madagascar for example, the future flows into the back of your head from behind. What they know is what happened in the past, so in their virtual space that is in front of them, where they can "see" it, but the future is unknown and therefore behind you, a virtual space that our senses can tell us in much less detail about.
So with Welsh creating sentences that can be either present or past, or both, or neither, I wonder whether Welsh time perception was cyclical in pre-industrial times.