If you go to Google.com and do a search and then try to restrict your search by custom date, you were out of luck over the past few days. The calendar dialog box would not let you click or select any dates. This has been a bug for the past few days and Google has just resolved it.
So when you try to bring up this feature, it simply did not let you select anything:
There are tons of complaints in the Google Web Search Help forums about this. There was no estimated time for a fix given but as of this morning, it is fixed.
One contributor in the forum who is labeled a "diamond product expert" said "I can reproduce this issue, and have referred it to the Google Search team for investigation."
Google also acknowledged it yesterday on Twitter:
We're aware that using the Custom Range option to restrict search results by date may cause a browser's tab to freeze. We hope to resolve this soon. In the meantime, the before: & after: commands can be used for date restriction. More here: https://t.co/5l4HON1pxB
— Google SearchLiaison (@searchliaison) January 19, 2021
As of this morning, January 20th, the issue is now resolved.
Forum discussion at Google Web Search Help.