You have 53 days left, meaning about 13.25 weeks, and therefore to gain 23 pounds you will have to gain about 1.7 pounds a week, which is not impossible, but by the end you will have a bit of fat to cut.
You're gonna have to eat about 865 extra calories above your maintenance level in order to gain weight at this rate. Definitely try to stick to a clean diet, with one or two cheat days in order to prevent too much fat gain.
Good luck.