Introduction to Layers in on-call schedules
Understand the basics of Layers in on-call scheduling and how it helps you bring flexibility into scheduling
Layers are schedules with the same key components as members, handoff, rotation and slots. You can add multiple layers to one on-call schedule. This helps you give flexibility over timings and members.
Layers for your on-call schedule are organised sequentially in ascending order. This means when timing overlaps between Layer 2 and Layer 1, the higher layer will overlap the lower ones, i.e. in this case Layer 2 will overlap 1.
For 3 layers, Layer 3 will take overlap over 1 and 2.
Every on-call schedule will have at least one layer
In simple words - if both layers have common times then Layer 2 will overlap calendar schedules from layer 1. Let's take an example.
Here is a simple on-call schedule with 2 members rotating each day. This means one of the members is on-call every day covering for the entire week.
All days - Daily rotation among 2 members

Just one layer to our schedule
This is how the calendar looks like with just the above layer in our on-call schedule

Calendar for above on-call schedule with just one layer
Now, this could be too much to handle. How about we give them a break over the weekend and ask other members to help out.
To enable this, we can add another layer with weekly rotation among members who only need to be on-call from Friday 6 PM to Monday 9 AM
Weekdays - Daily rotation among 2 members
Weekends - One person for the entire weekend rotating weekly

2 separate layers, one for weekday and another for weekend
Members from Layer 1 will be on-call every alternate day, on all weekdays and members from Layer 2 will be on-call for the entire alternate weekend (since weekly rotation has been applied).
This is how the calendar looks with both layers.

Calendar with 2 layers, one set of members for weekdays and another for weekend
Members from Layer 2 will overlap the scheduled on-call from Friday 6 PM to Monday 9 AM.
If the weekend layer was Layer 1 and the weekday layer was Layer 2 then the weekend layer would have never come to effect. There are no limits on number of layers to be added on a single on-call schedule
You can start experimenting with layers by editing the same schedule as many times as you want.
- Can I add a layer temporarily?
- You can add a layer and then delete it. A common use case if a person needs to take the day off and someone else has agreed to cover them, then add a new layer to cover that day alone. Once the day is passed, delete the layer.
- How many layers can I add?
- There is no limitation. Our recommendation is to avoid adding too many layers. Otherwise, it could get confusing how the calendar works and as a result teams usually hesitate to delete any layer.
- How many members can be added in one layer?
- There is no limit here either.