Date -in -out

Yesterday, after sending an email to customer and recognize I made a mistake about IN and OUT before a date value. That's ok, they still understand of course, but being a professional, I wonder myself that I should NOT repeat a basic mistake like this, especially I am Tester :) -I don't mean Tester has no error but try to make it as less as I can)

Let's see if this sentence is correct: "See you in Saturday night" or "She was born on July"...
>>Well, it must be "See you on Saturday night" or "She was born in July"... Sometime I am still confused about when using IN or OUT. Tonight, I decide to make this clear. Let's go...

Remember me, this actually was a topic of English class at LTRC, Mr. Marc feel very exciting when he saw his student having many confusing on this stuff. Me too, still embarrass sometimes, just write this down again to stick in mind. Here is the basic syntax I wrote down in my notebook:

On Saturday...(Monday, Tuesday..)
In the evening...(morning, afternoon)
But.. On Saturday evening
And.. at night (not in the night)

In 2008...
In January...
But... On January 1st..

Search in my favorite English site, I found a related quiz. Now, just give a quick shot, come to this quiz, just 5min, then you will kick it off :)