Photos are not organized by the real time...

I turn on icloud photo library on my iphone 6 on and ipad air 2
ad you know if you have turn on icloud photo library you can not sync photo from itunes in pc or mac
so if you want put some photo in your device you have to upload them into photo in www.icloud.com
but the problem is when you upload photos in www.icloud.com they will not organized in your device by the time they were taken
and all of them organized by the time you upload them !!
if you upload 100 photo from 5 years ago till a week ago all of them organized in the photo app for now !! because you upload them now !!
any one know why this happen ? and what is the soloution ?
thank you