DateTime fields for Toml Frontmatter should export as DateTimes, not Strings

[xelivous]

Followup to #228
It seems like datetime widgets are serializing to string format instead of raw datetimes. They can still be interpreted by most frontends in the "incorrect" format but it should still likely be fixed to follow the spec.

What it exports as right now:

+++
date = "2024-10-24T00:00:00"
+++

What it should be:

+++
date = 2024-10-24T00:00:00
+++

[kyoshino]

I forgot to mention this in #228. I know TOML has date format without quotes, but as per the DateTime widget spec, the data type is a string. I’ll check how Netlify/Decap CMS handles it. If there is incompatibility, I’ll fix it.

[kyoshino]

Just tested with Decap CMS and it also quoted dates when saving an entry as TOML:

date = "2024-10-25T06:55:00.000Z"

So this would be wontfix.

[kyoshino]

I’ve found a relevant Netlify/Decap CMS issue and developed a solution for this:

• Support date object on Date widget decaporg/decap-cms#3583

[kyoshino]

The native date/time format support landed in v0.43.0. Please reload the CMS to see the change.