---
search:
  tags:
    - Sessions
    - DELETE
seo:
  description: >-
    Return this session's data to an offset of 0. Reference for the DELETE
    /v1/sessions/id/{session_id}/unix-offset endpoint in the Roboto REST API.
sidebar:
  label: Clear unix offset
  badge: DELETE
title: Clear unix offset
type: openapi-operation
---
Return this session's data to an offset of 0.

Its stored timestamps are then read as nanoseconds since the Unix epoch with nothing added, and
the session's aggregate bounds are recomputed from the moved data. Reaches exactly the data
:py:func:`set_unix_offset` writes, and moves declared time ranges back the same way.

Accepts a session in any anchoring state. Repeating the call, or clearing a session with no anchor or
no topic data, changes nothing. A session made of slices anchored at several different instants clears too,
each slice moving back by its own anchor.

Returns the session record.

Two cases yield a 400: data with negative timestamps of its own, which an offset of 0 would place before
the Unix epoch, and a declared time range whose start would fall before the epoch once it moves back with
its data. A concurrent writer adding data to the session yields a 409; retry the request.

### Access control
 - Restricted tokens need the API scope `api.everything_else`

`DELETE /v1/sessions/id/{session_id}/unix-offset`