Repeat appointments

We use Rallly for regular twice per week meetings, to see who's going to be there each time. This means that after each meeting I delete the one that's just finished, and add another one on the end. It's easy enough to do - but would be even easier if we could specify e.g. "Meeting 1: every Wednesday 16:00-18:00 GMT / Meeting 2: every Saturday 17:00-19:00 GMT" and get Rallly to update them automatically, always showing e.g. the next 4 weeks. Google Calendar has a similar function I find invaluable...