Selection of the optimal time for meeting

It all started with a call to the hairdresser to schedule my arrival time for a haircut. At that time, the week was planned to be rather tense, a lot of things to do, meetings ... I open my diary, the person on the other end of the wire apparently looks into his schedule, then something like this follows:
- when is it convenient for you to come?
- tomorrow at 11:00 you can?
- no, only at one o'clock, before that everything is taken.
- Damn, at the hour will not work, but at 15:00?
- no, it's free from one to two and after four.
- and what the day after tomorrow? ..
on the 30th second it begins to resemble a kind of sea battle
- 11: 00-12: 00?
- by ... - 13: 00-14: 00?
- No, I did not hit)))

Of course, we quickly agreed, but it was then that I imagined how cool it would be to put our "maps" on each other in Photoshop and instantly see the free fields!
Later, I remembered how difficult it is for companies of 4 or more people to agree on a convenient time for everyone.

Actually the idea

1. The meeting participants create "time maps", marking the free cells in the calendar.
2. The program superimposes them (maps) on each other and shows a general map, where the cells, which marked the greater number of participants of the meeting, are somehow highlighted.
   

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Implementation (as I see it)

If we consider the implementation of the idea as a separate web service, then everything is simple, I think you have already guessed:

1. The visitor creates an appointment.
2. The meeting creator sends a link / invitation to the meeting to friends.
3. Each guest marks the free time in a certain time range specified by the creator of the meeting.
4. On the page of the meeting a community card is constantly hanging, which, in essence, is a superposition of the maps of all the participants of the meeting.

Then you can fantasize in any direction, someone probably already thought about the comments, tags, ratings, reports from meetings, and someone thought how like “overlay cards”, agree on a venue, in any case, this is already a fan of the rod .

Very interesting, maybe I was just looking bad, and for a long time there is something like that?