I agree, it's confusing. Easily understandable dates and times aren't WGT's strong suit.
But, OTOH, it's been how they've always dated multi-round tourneys. So, it shouldn't be a surprise to anyone who's been paying attention.
Golf is a game that has always emphasized the responsibility of the player to understand the rules. In real golf, you can post the best score, but if you make a mistake filling out your scorecard, you lose.