Date property time picker forces ISO format instead of respecting user-defined date format

Bug reports
1

Steps to reproduce

  1. Create a new note and add a date property in the Properties panel.
  2. Manually enter a datetime value using a custom format, for example:
    2026-02-01 16:53
  3. Open the “Date and time picker” for this property.
  4. Select any time from the picker.
  5. Observe the resulting value after the picker updates the field.

Expected result

  • The Date property should update the value using the same datetime format already used in the note or property (e.g., YYYY-MM-DD HH:mm).
  • The time picker should respect the user’s chosen date format instead of overriding it.

Actual result

  • After selecting a time in the Date and time picker, Obsidian rewrites the value into ISO 8601 format:
    2026-02-01T16:53:00
  • This happens even when the existing value uses a different format such as 2026-02-01 16:53.
  • The forced ISO format breaks workflows that rely on custom datetime formats.

Environment

SYSTEM INFO:
	Obsidian version: v1.11.5
	Installer version: v1.11.5
	Operating system: Windows 11 Pro for Workstations 10.0.26200
	Login status: not logged in
	Language: en
	Insider build toggle: off
	Live preview: on
	Base theme: dark
	Community theme: none
	Snippets enabled: 0
	Restricted mode: off
	Plugins installed: 0
	Plugins enabled: 0
2

I’m not entirely sure (as I’m on Mac) but I don’t think this is necessarily a bug :thinking: :woman_shrugging: …

I mean, AFAIK and per the FR below, Obsidian saves date and date & time values in Source mode as YYYY-MM-DD and YYYY-MM-DD[T]HH:mm:ss respectively when adding the values through Properties (either manually or using the date/time picker in Live Preview).

The formatted date/time values you see in Properties (in Live Preview/Reading mode) has always been just a display of the saved values in Source mode…