Google has finally fixed the set a reminder feature in Google search. We first reported the issue a few weeks ago and I’ve been tracking it since and as of yesterday, last night specifically, the feature started working again.
In short, you can go to Google and search for [set a reminder] or something like [remind me to do X] or something similar and Google will let you set the reminder directly in search. The reminder will be added to your Google Calendars and Google reminders feature.
Here are screen shots of it working this morning in Google search:

Andy B from Google wrote in the ongoing Google Webmaster Help thread:

Great news! I can confirm this issue should now be fixed for all users. Many thanks again for your reports and continued patience while we worked to resolve this.
If you’re still running into problems creating reminders on Chrome desktop, please read through this help center article outlining common reasons why you may not be seeing the option.

Forum discussion at Google Webmaster Help.

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