[voice]
I think Sentience is doing it on purpose. It's hard to feel like the days are going by slowly, like in a real prison, when you're not really sure how much time has passed.
I guess you could always scratch lines in the wall. [An unseen smirk.]
Though you're right... It does make anniversaries from our home worlds hard to observe. [He'd almost said "celebrate", but what he was thinking of wasn't a pleasant event.]