"after three days": Was Jesus really crucified on a Wednesday?

Any time this week approaches, someone inevitably poses the question: 

"Was Jesus' resurrection really three days after his death? Friday afternoon to Sunday Morning seems more like a day and a half."

In the past, I've aligned myself with the traditional church calendar usually by following in the footsteps of Martin Luther's defense - "but Jesus was dead at some point on each of those three days - Friday, Saturday, and at least for a little bit on Sunday." 

However, Jesus' words in Matthew 12:39-40 have always troubled me - "three days and three nights in the heart of the earth." In this case, the Lutheran defense, which would require a Sunday (or Thurs) night addition, does not seem to hold up. 

Nothing consequential to the reality of the resurrection is at stake here - except for, of course, the matter of Scriptural inerrancy. Is all of Scripture true as it was originally composed? My worry, accordingly, is keeping to the traditional church calendar. If we are saying history lines up with the Friday-Sun church calendar, are we not in danger of invalidating verses like Matthew 12:40 or Mark 8:31 ("after three days")?

In this linked article Josh Claybourn makes a compelling case for a Wednesday crucifixion. Below is a visual that helps with the Wednesday-theory chronology of events.

To be fair, there are plenty of legitimate dissenting opinions (just check out the comment section in the above article). One problem with the Wed idea is it seems to make for 4 nights in the tomb! Perhaps it was a Thursday, as is argued here. 

And don't worry, SCCers, our Tenebrae Good Friday service tomorrow night is still a-go. Any time is a good time to reflect upon and be moved by the agonies of the cross endured by Jesus on our behalf.