In this paper, distributed iterative time slot allocation algorithms for spectrum sensing information (SSI) sharing in cognitive radio ad hoc networks are proposed. The proposed algorithms are based on a collision detection and acknowledgment scheme, which allows nodes to receive knowledge about collisions with their two-hop neighbors. The nodes use this information to update their operating time slots using a probabilistic approach, i.e., each node maintains a parameter representing the probability of switching the time slot in case of a collision. Both fixed and adaptive probability based schemes are proposed. Simulation results show the rapid convergence and excellent performance of the proposed time slot allocation algorithms.