The most convenient ordering is for what's most important, so (Day) Day number/Month/Year, as you almost always care more about what day it is rather than what year. As for time, it changed far faster than the day does so would be weird, especially if you add seconds, plus in MOST languages you actually read the hour first then the minutes, unlike how it's done in English.
I don't think the order matters for convince, you'll get used to your date system and instinctively look at where the day is. We're not computers, we're not stuck to strictly read left to right, we can jump around