  We investigate the size of discrete time crystals s (ratio of response period
to driving period) that can be created for a Bose-Einstein condensate (BEC)
bouncing resonantly on an oscillating mirror. We find that time crystals can be
created with sizes in the range s = 20 - 100 and that such big time crystals
are easier to realize experimentally than a period-doubling (s = 2) time
crystal because they require either a larger drop height or a smaller number of
bounces on the mirror. We also investigate the effects of having a realistic
soft Gaussian potential mirror for the bouncing BEC, such as that produced by a
repulsive light-sheet, which is found to make the experiment easier to
implement than a hard-wall potential mirror. Finally, we discuss the choice of
atomic system for creating time crystals based on a bouncing BEC and present an
experimental protocol for realizing big time crystals. Such big time crystals
provide a flexible platform for investigating a broad range of non-trivial
condensed matter phenomena in the time domain.
