I don’t know if it depends on the timezone you are in, or what’s happening. For me a date with no time seems to default to noon (12pm), where I would expect it to default to midnight. I can’t reproduce the situation where it jumps to the wrong day. Seems like the time jumps forward for me, but it jumps backward for others. Even in cases where ai specify a time, it jumps ahead 12 hours.
Something is definitely off, but I can’t quite put my finger on it. I mention more on it is this post.