Various aspects of the present disclosure generally relate to wireless communication in a shared spectrum. In some aspects, a user equipment may receive an indication of a set of starting offsets for an uplink communication, wherein the set of starting offsets includes at least one negative starting offset relative to a start of a slot or a mini-slot in which the uplink communication is configured to start; select a starting offset from the set of starting offsets; and transmit the uplink communication, wherein the uplink communication starts at a time indicated by the selected starting offset. Numerous other aspects are provided.