Systems and methods for determining a timing of a random access channel (RACH) occasion (RO) used to transmit a contention free random access (CFRA) preamble triggered by the receipt of an physical downlink control channel (PDCCH) order in a PDCCH are disclosed herein. A user equipment (UE) receives the PDCCH order and determines a timing offset value between the RO and a signal (e.g., a synchronization signal block (SSB), the PDCCH, a reference signal, etc.) to be used as a timing source. The UE also determines the arrival time of the signal to be used at the timing source. The UE then determines a time of the RO (during which the CFRA preamble will be transmitted) according to the arrival time and the timing offset value. Timing advance (TA) value(s) may also be accounted for as part of such a determination.