TomTime allows the user to pick traveltimes and amplitudes, and save those data with source and receiver 3-D coordinates in the format used as input by the tomography program GeoTomCG. The most common format is: Ray Identifier (integer) Source X, Y, Z Receiver X, Y, Z Time Amplitude (optional) e.g. 17 10. 0. 155. 120. 0. 145. 35.30 1560 A user who wants to pick traveltimes in the most common seismograph files without reading much of the manual can begin by following the instructions in this section. Only the most commonly used options are described.