Various aspects of the present disclosure generally relate to wireless communication. In some aspects, an aerial user equipment (UE) may measure a first offset associated with a downlink frame based at least in part on a time when a downlink signal is received from a terrestrial base station. The aerial UE may determine a second offset corresponding to a starting time for the downlink frame at the terrestrial base station. The aerial UE may transmit an uplink message in an uplink frame using a timing advance that is based at least in part on a value of the first offset and a value of the second offset relative to a starting time associated with a global navigation satellite system frame duration. Numerous other aspects are described.