It would be great if the date field could accommodate not only minute-level precision, but also month-level or year-level precision. If it would be possible to mix different precision levels (like only year in one row and full date in another) that’d be the most helpful.
Usecase: In some cases, it is not possible to have the same level of date accuracy for all items in a row. For instance, in a database of publications, newspapers contain the exact date they were published on, books only have year-level information.
This is a wonderful feature request! But I wonder if Excel, Google sheet or Airtable offer this feature, because I can imagine the complexity of the menu then (four drop-down items year, month, day and minute even for each cell) and the confusion it could cause. Nevertheless if you calculate this column in a formula it could bring even more errors and confusion.
This is because such a combination of formats in one column won’t fit to a database. From the database point of view, when the exact date information of one date is missing (i.e. you only have the publication year), to maintain the database’s format, you can enter the 1st of January for this year as a pseudo date (i.e. “2017-01-01”).
This is how wikibase does it on the user interface level:
Obviously the “10,000 years” precision is a bit funny 
Probably seatable wouldn’t need that. But the user interface is not complicated.
In Wikibase, the date precision is stored in the database together with the date value. For calculations, January 1st of the year will be assumed in the illustrated case. Ideally that could be adaptive based on the calculations I want to perform.
I see!
Only adding to the discussion: It is possible to display only the year or the month if you are using SeaTable as a backstage database. See Present your data with SeaTable on your website with PHP
