I have done a few rag quilts. I did not keep track of time (I work full time), but a few tips to make it go faster next time.
Rip the fabric into long strips, yes the edges are a bit rough, but you have wide seam allowances and will be snipping them, so it does not matter.
Stack your long strips and cut your squares using a ruler and rotary cutter. Once again not the most accurate way to cut, but not terribly important in a rag quilt.
Do not use batting, this saves two steps, one you do not have to cut the batting, two you do not have to do X's on each square.
Or just an extra layer of flannel, cut as above and do not worry about the X's.
Use recycled jeans for the back, this does take quite a bit of time, but you can have fun with the details on the jeans, I used interesting seams, pockets even a fly or two. You do not need batting if you use denim. The quilt will be very heavy.
Do yourself a favour and buy a pair of spring loaded snips to do the snipping. I did the snipping over a few evenings while watching TV.