Olivia's pocket universe was a fully self-contained dimension where she possessed absolute dominion over its internal aspects, from the level of cosmic energy within it to the laws of physics and space-time.
As such, altering the rate at which time flowed inside it naturally fell under that authority, since time itself was part of the dimensional framework.
Because of this, she and Richard could spend extended periods dissecting and experimenting on the Dead Lifeforms they captured, even while the war outside the pocket universe was still ongoing.
She used Estea's calendar system within it, so a 'day' inside was counted after 24 hours had passed, and she intended to adjust the ratio of internal to external time to 10:1, meaning that even if ten days passed inside, only a single day would pass outside.
