# Layers in on-call schedules

## What are Layers in on-call schedules?

In Spike.sh's on-call scheduling, 'Layers' add a dynamic dimension to your planning. Each layer encompasses essential elements like members, handoff times, rotations, and slots. The flexibility of adding multiple layers to a single schedule empowers you to customize timings and team involvement with precision.

Layers are meticulously organized in a sequential, ascending order. This design means that in instances of overlapping schedules, the higher layer takes precedence. For example, if Layer 2's timing intersects with that of Layer 1, Layer 2 will be the active layer, overriding Layer 1. Similarly, in a configuration with three layers, Layer 3 would supersede both Layers 1 and 2 in overlapping scenarios.

This layered approach ensures a seamless, well-coordinated on-call schedule, allowing for nuanced control over who is on-call and when..

{% hint style="warning" %}
Every on-call schedule will have at least one layer.
{% endhint %}

### What does overlapping mean?

'Overlapping' in layered scheduling is straightforward: when two layers share common times, the higher layer takes precedence. To illustrate, if Layer 1 and Layer 2 have overlapping schedules, Layer 2 will be the active one, effectively overriding the schedules set in Layer 1.

### Understand layers with 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](https://1743514643-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Ln3jS1bJTTsE3yoEcOu%2Fuploads%2Fgit-blob-78f7c4be15fa53ed5efc1c57c1d8329183ffa5fc%2Flayer-1.png?alt=media\&token=af05f43b-5986-47bf-b304-089982413f90)

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](https://1743514643-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Ln3jS1bJTTsE3yoEcOu%2Fuploads%2Fgit-blob-1a1daef9146162aa6dcc892dc5bbcd9000500f2e%2Foncall-update-after-another-layer-e.png?alt=media)

### Adding the weekend layer to override

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](https://1743514643-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Ln3jS1bJTTsE3yoEcOu%2Fuploads%2Fgit-blob-56938114669d0267b3f5265df68ddf5e1825f841%2Fweekday-weekend-desc.png?alt=media\&token=54592798-ef80-438d-a186-b1c1d43fe22f)

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](https://1743514643-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Ln3jS1bJTTsE3yoEcOu%2Fuploads%2Fgit-blob-3e9d417ff57eccb7fe5ce9a893d8d09bc35b9691%2Fimage.png?alt=media\&token=614b86d5-9d6f-4828-8f44-bf689f646df8)

### **How did overlapping work here?**

Members from Layer 2 will overlap the scheduled on-call from Friday 6 PM to Monday 9 AM.

{% hint style="info" %}
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**
{% endhint %}

You can start experimenting with layers by editing the same schedule as many times as you want.

### FAQs on Layers

* **Can I add a layer temporarily?**
  * Yes, you can. Alternatively, also check out [On-call overrides](https://docs.spike.sh/oncall-schedules/override-an-on-call).
* **How many layers can I add?**
  * There is no limitation. Our recommendation is to avoid adding too many layers. It could get confusing how the schedule 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.