Retirement tax questions

Thanks so much Alicia!

 

last question, what would be the deadline for those additional contributions?

 

I live in california, so I understand the deadline was extended until Oct 16th (source: https://www.irs.gov/newsroom/irs-may-15-tax-deadline-extended-to-oct-16-for-disaster-area-taxpayers-...)

 

However, it is not clear to me if that deadline applies as both employer (profit sharing) and employee.