The pulsed properties of synchrotron radiation are being applied extensively for subnanosecond timing studies. Measurements in the time domain take advantage of the well defined time structure, unique tunability, wavelength registration, and polarisation characteristics of synchrotron radiation. A description of the time modulation of synchrotron radiation is followed by a comparison between several subnanosecond timing techniques which have been used at the Synchrotron Radiation Source (SRS) at Daresbury. The present limitations of time-resolved fluorescence measurements and the broad range of possible applications of these methods, are illustrated by some selected examples. In the near future time-domain measurements will be improved to give a resolution of a few picoseconds and will be extended to include excitation over a range of wavelengths in the x-ray, vacuum ultraviolet and infra-red regions.