Outlook: highly unlikely. Post offices are closed on Sundays. They may have people working inside sorting mail and packages overnight or something on Sunday, but I wouldn't expect your package until Monday.

You answered your own question.

Closed on Sunday.

no it will be delivered on monday

No

I missed a package yesterday, a Saturday, however they left a note saying I had to schedule a redelivery, so I did so, scheduled it on a the very next day, Sunday.

However other online articles has me doubting if it will come today or not, even though the USPS redelivery website gave me the option to choose a Sunday.

Will USPS deliver it today? There's no way I can call them since their offices are closed on Sunday.