This article describes
In Slack, timezone settings are configured on a per-person basis only. If you are traveling outside of your normal time zone, setting your current local time within Slack will make sure that your Slack reminders and Do Not Disturb hours happen in your current local time.
Please remain aware that other people within your workspace may not be in the same time zone, and exercise discretion over the use of the Slack announcements feature including @everyone or @channel. For more information, see Slack's "Notify a channel or workspace" help page.
For more information on Do Not Disturb and snooze settings: Slack's "Pause notifications with Do Not Disturb" page.