I applied to a job online, filled out the application, submitted, etc. However it's a chain and so a week later I applied to multiple one, and it automatically submits the original one I did; which is quite unfortunate because I wanted to change the hours I put down (wasn't sure sure about my plans for the summer). The only way I can think of is making a new account for the job with a different email, however i'd use the same SSN.. Is that illegal or would they notice it?

It wouldn't be illegal as long as ur personal u out down matches the info of th SS# u give them

However that being said it may/may not be fround upon by the company by submiting multiple applications using differant info to do it

If u have the option to correct ur application or email them.... I'd suggest doing that to change the information u provided

its legal in my opinion

Its only legal if ur personal information matches ur SS# (name, birthday, etc)

Contact info can vary (address, phone #, email address) as ppl move or change providers

However multiple application with varying availability & contact info may give an apperance of somene who jumps areound a lot & may/may not give the best impression to a perspective employeer

You probably could just talk to them about the hours if you get called for an interview. Say that you applied to several of their locations and the online application didn't allow you to change desired hours.
that'd probably be better than trying to make a new account on their site.