Does "return due date,(whichever is later)" means im going to get a refund on that date

No. Where exactly are you seeing this?

On the account transcripts

Will ordering a transcript help me determine when I’ll get my refund?
No, a tax transcript won’t help you determine when you’ll get your refund. IRS transcripts are best and most often used to validate past income and tax filing status for mortgage, student and small business loan applications and to help with tax preparation.

The codes listed on tax transcripts don’t provide any early insight into when a refund will be issued. The best way to check on your refund is by visiting  Where's My Refund? . 

https://www.irs.gov/Individuals/Get-Transcript-FAQs

I seen it on my IRS transcript