Starting today, you can instruct Jolly to group all the celebrations into a single message. Prior to this change, if several people have their birthday or work anniversary on the same day, Jolly will send an individual celebration message for every person.
Now, you can change this by clicking “Settings” within Jolly and enabling message grouping. If you have a large team, this is a great way to prevent a large number of messages from coming into your Slack channel.
If you still haven’t tried Jolly, now is the time to do so: https://usejolly.com