Bulk/weight gain

28, M, 5'4 and 110 pounds.

I calculated that my required calories would be 2,272 per day to gain 0.5 pound. Which would be around 15,904 per week. I tend to eat more on Saturday because that is when I usually eat out at restaurants.

Let's say (hypothetical scenario)

I eat 2100 calories from Sunday to Friday which totals up to 12,600. Then, eat like around 3500 calories one day on Saturday. If (hypothetically) I eat like this one week, then I would in a caloric surplus right?!

LOL. I'm sorry if it's a silly question. The math makes sense to me, but for some reason, I'm finding it hard to gain weight still.