3:37 PM
(Noting that they can disagree with the observer at the front of the other ship about the distance to the observer in the back of the ship.)
And if that seems perfectly obvious, consider two observer ships at rest with each other, both docked at either end of a one light-minute long tube, and consider what Lorentz contraction might lead you to expect to happen to the distance between them when one undocks and starts accelerating towards the other.
And if it now seems obvious that they can disagree on distance, that implies that two ships can tell which is really moving just by flashing lights at each other to communicate distance, and whoever measures the shorter distance is the one who is really moving; indeed, a docking contraption such as just described in that observer's reference frame would appear to extend, rather than contract, when that observer moved to the reference frame of the observer measuring the longer distance.