Hey there @Xiaomeng14001 - great post! Thanks so much for the description of your use case re: this feature request.
While, as you said, we have this request recorded already (and looped around to product; I will add your request to that bunch!) and there is nothing I can do to implement the feature now, for your specific use case there is a workaround I’d love to suggest!
If you are using one-on-one event types for this need, rather than creating weekly availability consider using date specific hours/date overrides.
Create a date override for each date you’d like to take meetings, and (for example - if each meeting is one hour long) create only the number of hour long meetings on each of those dates that you’d need in order to make up the exact total number of bookings you’d like for your research. This way, you can send the link to as many people as you’d like, but once of those date specific time slots is booked the event will no longer appear as bookable to anybody. You can combine this method with setting a date range for date X to date Y so that bookings can only be made within a certain time frame (regardless of when the actual dates you’ve opened up for booking are). For example, if you are meeting with everyone in January but want all dates booked by mid-December, create a date range from now until December 15th so nobody can book once December 15th comes and goes.
You can read more about these settings in our Help Center articles and community topics below:
Availability Schedules
I’ve never used this method. Some of it sounds interesting. But it’s not very suitable for my need. I want to give my potential participants as much flexibility as possible. I invite people from around the world, so their preferred hours could be all very different. For example. I usually have at least a 1-week timeframe for people to book 1-hour meetings with me. People can book any time that I’m available. And out of all this time, I’m really only aiming to get 5 - 7 meetings.
So, using the method suggested would require me to be much more restrictive in when people can book. And it’s very likely that the people I’m inviting to book will not find a timeslot that works for them, and skip booking all together, resulting in me not getting enough participants.
@Xiaomeng14001 understood. There might not be a perfect workaround for your use case right now, and I do apologize for that (I hate not having the perfect solution for every customer!) - but let’s brainstorm a bit more.
Have you looked into our Meeting Polls feature? Here's a great article that explains our Meeting Polls feature!
Once participants have voted in your poll, you can decide on the preferred time to schedule the meeting.
- In your Calendly account, go to your Scheduled events page.
- Select the Pending tab.
- Find your preferred time to have the meeting, and select Book meeting time.
- Confirm the invitee list looks correct, and then select Book meeting.
After you book
You and your invitees will receive a calendar invitation with the meeting details and location.
You might also want to look into our Calendly Routing Forms feature, our Customize Once and Share feature and our One-Off Meeting feature. While I understand your goal is to send one link to many people and allow for open booking with cutoff after a certain number, that isn’t all going to be possible right now. You can get some, not all, of those goals met with each of these features.
In the meantime as promised I have looped your feedback around to our product team for future consideration. We do get this request somewhat commonly, so hopefully it’ll eventually be implemented! I hope this helps!
@Kelsi at Calendly I really appreciate your prompt responses and all these alternative ideas you shared! 
The meeting poll is another interesting feature that I’ve not used. I feel that it is more useful when trying to reconcile availability with a large number of people, for a single meeting. For my purpose, it seems to add a bit of unnecessary overhead for both the host and the invitee.
For the host - I need to review all the pending events, and book meetings with individual participants, so my meeting with one person doesn’t overlap with another.
For the invitee - instead of just choose one time slot that works best for them, they have to propose multiple time slots. They also won’t get that immediate confirmation, and know which of their proposed time slots are booked.
In my context, I really want to make things as easy as possible for these potential participants, because they are doing us a favor by providing feedback to improve our product. So, I would always favor solutions that gives my invitees the best experience.
So, Thanks for promising to pass this request to your product team! Hope to a feature like this soon.
Hey again! You are so welcome - I’m sorry I cannot give you a viable workaround in the moment, though! Have a great week!
I just want to say as a UX Researcher, I face the same exact predicament as Xiaomeng. Looking forward to Calendly implementing this feature request.
Agreed that we would love this feature ASAP! Thanks for the offering of potential work-arounds for the time being.
Just chiming in to +1 this. 
I am a coach, and I share groups of clients with other coaches. We are independent of one another and have our own Calendly accounts.
In a recent situation, for example, a colleague and I need to meet once, over the course of a month, with each of 24 people. I can only manage 8 of these meetings, and my colleague will handle 16. We’d each like to be able to set up an event type that will become unavailable when those thresholds have been reached. Thank you!!
Hey @Andrea198300, @Smart13342 and @Jennifer67087 - thanks so much for adding your use cases to this feature request! Please rest assured that your voices are being heard and we are adding this to our product roundup to report to the product team at the end of the month! While we cannot make promises regarding if or when new features will be implemented in the future we can promise the product team is always considering user feedback when making changes to improve Calendly. Have a great weekend, y’all!
Upvoting as well. I’m a rabbi and I absolutely must give my community members flexibility when they schedule with me, but I cannot have all the available slots book up. Even better than a limit on 1 event type would be for all events. Thanks. Please keep us posted on when this feature will come out.
Currently facing this same dilemma when setting up in-person UX research… do I open up an event to multiple days (and commute to the location each day) or make a big block on one day and hope enough people can make it? 
a painful choice. It would be wonderful to see this option in the future!
Oh, man, I was so sure Calendly had this feature and I just realized it does not! I also conduct interviews where I need to offer a finite amount of slots over a time period much greater than one day. Can’t believe this feature has not been built yet. 
Hey @Joseph80404 and everyone else commenting - we see and hear you! AND we have another string of comments going on over on this post regarding this same feature request! Exciting news - one of our Cal Pals posted an update about this feature being implemented soon, and asked our users (that’s you!) to continue commenting with explanations of exactly how you’d like to see it work and what your use cases look like. Head to that topic to learn more! I am going to close this topic to comments in hopes that it helps redirect traffic to that one - see you there!
