I'm afraid you have missed the point. My point is that most of the time you don't need datetimes. You only need dates.

Think about sites like blogs. The user only needs to know on what date a blogpost is published. Likewise for newspapers: we have hundreds of years of paper newspapers where people know on what date an article is published but not at what time. Think about banks. My bank tells me the date of a transaction, not its time. Likewise for brokerages.