# Leap second or clock skew

> A leap second repeated a second of the clock. Timers fired twice, leases expired early, and requests and locks across one region timed out.

## What happens

A leap second repeated a second of the clock. Timers fired twice, leases expired early, and requests and locks across one region timed out.

## How to prevent it

Leap smearing spreads the second over a day, so no clock ever jumps.

The postmortem opens the first of these that you do not own yet:

- [Leap smearing](https://wiki.playquorum.dev/research/leap-smearing.md)

## Components it hits

[App Server](https://wiki.playquorum.dev/components/server.md)

## Facts

SEV1 Leap second or clock skew
- **First Era:** [Series C](https://wiki.playquorum.dev/eras/series-c.md)
- **Starts at:** SEV1
- **Escalates to:** SEVnull
- **Lasts:** 1 min

## See also

- [Incidents](https://wiki.playquorum.dev/incidents.md)

Source: https://wiki.playquorum.dev/incidents/leap-second