Design Doc for the From and Until Timestamps fix for OOO

Problem Statement

• As of now when a user selects OOO from website-my, the timestamp is stored as the 00:00:00 UTC timestamp for the chosen date.
• Problem arises when the user chooses to be on OOO for one day. Suppose a user chooses to be on OOO from 02/10/2023 till 02/10/2023, then both the from and until timestamps are chosen as the 00:00:00 UTC timestamps for both. In this case, 1696204800000.
• Hence, the from and until timestamps become equal resulting in a OOO for 0 ms. This would cause problems when updating the OOO dates in the user's discord nickname.
• With this issue, the from and until timestamp for the day must be set to 00:00:00 UTC and 23:59:59 UTC respectively.

Refer to the screenshot higlighting the issue

Solution

• As the from timestamp is correct i.e at UTC 00:00:00. We will need to convert the to timestamp to respective time of the day at 23:59:59 UTC`.
• This needs to be done at all the places where the user is being marked as OOO.

Issue Ticket : https://github.com/Real-Dev-Squad/website-backend/issues/1579

ETA Breakdown:

• Design Doc: 1 day
• Code Changes : 1 day
• Tests : 1 day
• Review+Buffer: 3 day
• Completion : 9th Oct 2023

Please feel free to add any comments if you have any suggestions / improvements.