Is it really untrue? Seems there is something to it, although maybe not unilateral right, but certainly there some language around flexibility up to 3 hours in the Act.

Maybe some Finnish lawyers chip in here on the actual interpretation of this?

Section 13. "Flexible working hours":

"When working hours are flexible, the regular daily working hours shall be extended or reduced by a flexible period of no more than three hours."

https://www.ilo.org/dyn/natlex/docs/ELECTRONIC/46245/60791/F...