Whenever I am asked for availability for proposed meetings, I continue to make use of the excellent web application TimetoMeet that allows me to graphically detail times I can offer on a web calendar from which they can select or add their own suggestions if none suit. It’s especially invaluable when the number of attendees is 3+.
Whilst there are many similar services now available e.g. timebridge, I’ve found irritations or restrictions with them that drag me back to TimetoMeet. The free service is great but the premium version has some important features worth paying for including synchronising your own ical feeds with the service. Hence I can see my existing calendar entries from within TimetoMeet when I am offering times.
Only one thing would make it better, which is something Timebridge do, namely whenever a meeting time is fixed via the service, it automatically removes this time slots from on other pending meeting invitations. i.e. you may offer several independent groups the same set of times to choose from and when a time is fixed with one group, it can no longer be available to the others.
If you have to arrange meetings with anyone, give it a try next time and see how beneficial it is in time saved.