An apparatus for conducting a blasting event, the apparatus comprising: at least one blasting machine that in use sends command signals (10a,10b,10c) to a plurality of associated detonator assemblies (12a,12b,12c); a plurality of detonator assemblies (12a,12b,12c) that in use are in signal communication with said at least one blasting machine, each detonator assembly (12a,12b,12c) comprising: (i) a detonator (13a,13b,13c) including a base charge (14a,14b,14c) connected to a firing circuit (15a,15b,15c); (ii) a storage component (16a,16b,16c); (iii) a countdown oscillator (17a,17b,17c); at least one high-accuracy clock in communication with, or forming an integral component of, each detonator assembly (12a,12b,12c), and comprising a transmitter that in use transmits a blast-rehearsal start signal and a blast-rehearsal stop signal to each countdown oscillator (17a,17b,17c) of each associated detonator assembly (12a,12b,12c), said signals being temporally separated by a time period corresponding to a desired delay time individually selected for each detonator assembly (12a,12b,12c), each oscillator (17a,17b,17c) counting a number of oscillations between said signals to determine a total oscillation count for each oscillator (17a,17b,17c) corresponding to said desired delay time, wherein in use the storage component (16a,16b,16c) stores the total oscillator count corresponding to the desired delay time and wherein in use receipt by said at least one detonator assembly (12a,12b,12c) of a command signal to FIRE from said at least one blasting machine, each countdown oscillator (17a,17b,17c) counting down its total oscillation count, thereby to achieve timed actuation of each detonator (13a,13b,13c) in accordance with its desired delay time. at least one blasting machine that in use sends command signals (10a,10b,10c) to a plurality of associated detonator assemblies (12a,12b,12c); a plurality of detonator assemblies (12a,12b,12c) that in use are in signal communication with said at least one blasting machine, each detonator assembly (12a,12b,12c) comprising: (i) a detonator (13a,13b,13c) including a base charge (14a,14b,14c) connected to a firing circuit (15a,15b,15c); (ii) a storage component (16a,16b,16c); (iii) a countdown oscillator (17a,17b,17c); (i) a detonator (13a,13b,13c) including a base charge (14a,14b,14c) connected to a firing circuit (15a,15b,15c); (ii) a storage component (16a,16b,16c); (iii) a countdown oscillator (17a,17b,17c); at least one high-accuracy clock in communication with, or forming an integral component of, each detonator assembly (12a,12b,12c), and comprising a transmitter that in use transmits a blast-rehearsal start signal and a blast-rehearsal stop signal to each countdown oscillator (17a,17b,17c) of each associated detonator assembly (12a,12b,12c), said signals being temporally separated by a time period corresponding to a desired delay time individually selected for each detonator assembly (12a,12b,12c), each oscillator (17a,17b,17c) counting a number of oscillations between said signals to determine a total oscillation count for each oscillator (17a,17b,17c) corresponding to said desired delay time, wherein in use the storage component (16a,16b,16c) stores the total oscillator count corresponding to the desired delay time and wherein in use receipt by said at least one detonator assembly (12a,12b,12c) of a command signal to FIRE from said at least one blasting machine, each countdown oscillator (17a,17b,17c) counting down its total oscillation count, thereby to achieve timed actuation of each detonator (13a,13b,13c) in accordance with its desired delay time.