Offer Expiration Time

Long story short I've received an offer from Boeing July 2nd in the afternoon. In the letter it said we need a response within 2 business days.

My question is, does that mean July 3rd is my last day to accept? I assume since July 3rd is an observed holiday I have until Monday July 6th EOD.

I emailed the recruiter for clarification and called but I received no reply (no doubt because the long weekend is looming)

Any thoughts? Just wanting the weekend to think it over and speak with family.