Here's what will be airing on FX and FXX on April Fools' Day, all times Eastern:

FX:

7am-According to Jim: "The Smell of Success" (S2E15, OAD: January 28, 2003)
7:30am-Big (RD: June 3, 1988)
9:30am-Lyle, Lyle, Crocodile (RD: October 7, 2022)
12pm-The Garfield Movie (RD: May 24, 2024)
2pm-Garfield: A Tail of Two Kittens (RD: June 16, 2003)
3:30pm-The Garfield Movie (RD: May 24, 2024)
5:30pm-Uncharted (RD: February 18, 2022)
8pm-Jumanji: Welcome to the Jungle (RD: December 20, 2017)
10:30pm-Jumanji: Welcome to the Jungle (RD: December 20, 2017)
1am-Date Night (RD: April 9, 2010)
3am-What Happens in Vegas (RD: May 9, 2008)

FXX:

7am-See How They Run (RD: September 16, 2022)
9am-The King's Man (RD: December 22, 2021)
12pm-The Menu (RD: November 18, 2022)
2:30pm-The Simpsons: "Radio Bart" (S3E13, OAD: January 9, 1992)
3pm-The Simpsons: "Dial 'N' for Nerder" (S19E14, OAD: March 9, 2008)
3:30pm-The Simpsons: "Parks and Greens" (S21E6, OAD: November 22, 2009)
4pm-The Simpsons: "Postcards from the Wedge" (S21E14, OAD: March 14, 2010)
4:30pm-The Simpsons: "Dark Knight Court" (S24E16, OAD: March 17, 2013)
5pm-The Simpsons: "Treehouse of Horror XXVI" (S27E5, OAD: October 25, 2015)
5:30pm-The Simpsons: "Fears of a Clown" (S29E14, OAD: April 1, 2018)
6pm-The Simpsons: "So It's Come to This: A Simpsons Clip Show" (S4E18, OAD: April 1, 1993)
6:30pm-Bob's Burgers: "What a (April) Fool Believes" (S13E16, OAD: March 19, 2023)
7pm-Family Guy: "April in Quahog" (S8E16, OAD: April 11, 2010)
7:30pm-Family Guy: "Yacht Rocky" (S18E1, OAD: September 29, 2019)
8pm-Family Guy: "Bri-Da" (S18E2, OAD: October 6, 2019)
8:30pm-Family Guy: "Absolutely Babulous" (S18E3, OAD: October 13, 2019)
9pm-Family Guy: "Disney's The Reboot" (S18E4, OAD: October 20, 2019)
9:30pm-Family Guy: "Cat Fight" (S18E5, OAD: November 3, 2019)
10pm-Family Guy: "Peter & Lois' Wedding" (S18E6, November 10, 2019)
10:30pm-Family Guy: "Heart Burn" (S18E7, OAD: November 17, 2019)
11pm-Family Guy: "Shanksgiving" (S18E8, OAD: November 24, 2019)
11:30pm-Family Guy: "Christmas Is Coming" (S18E9, OAD: December 15, 2019)
12am-Futurama: "Decision 3012" (S7E3, OAD: June 27, 2012)
12:30am-Futurama: "The Thief of Baghead" (S7E4, OAD: July 4, 2012)
1am-Futurama: "Zapp Dingbat" (S7E5, OAD: July 11, 2012)
1:30am-Futurama: "The Butterjunk Effect" (S7E6, OAD: July 18, 2012)
2am-King of the Hill: "Old Glory" (S4E11, OAD: January 9, 2000)
2:30am-King of the Hill: "Rodeo Days" (S4E12, OAD: January 16, 2000)
3am-King of the Hill: "Hanky Panky" (S4E13, OAD: February 6, 2000)
3:30am-King of the Hill: "High Anxiety" (S4E14, OAD: February 13, 2000)