Change timeformat in livechat window to 24h?

Description

In the livechat window which is integrated in an website, the time format is 12 AM/PM.
livechat-window

Since we are in Germany I would like to change the time format to 24h.
As a Livechat Manager I can see the time like 12:00 or 12:30 without any AM/PM in the preview.

Where can I set the time format for the live chat to 24h-format?

Server Setup Information

  • Version of Rocket.Chat Server: 1.3.2
  • Operating System: Ubuntu 18.04
  • Deployment Method: SNAP
  • Number of Running Instances: 1
  • DB Replicaset Oplog: no
  • NodeJS Version: 8.11.4
  • MongoDB Version: 4.0.13
  • Firewalls involved: ?