Feel free to tell lies on the 4th... you can always make up for it on the 30th. The former is "Tell a Lie Day"... while the latter is "National Honesty Day".
Patch things up on the 2nd with "Reconciliation Day", knowing that if all else fails you can really go to town on the 14th with "Ex-Spouse Day". On the 9th, give yourself whatever name you've always wanted, while the very next day being careful to take back all the names you ever gave to your brothers/sisters. Yes... "National Siblings Day" rides hot on the heels of "Name Yourself Day".
"Peanut Butter and Jelly Day" can be celebrated on the 2nd, with Caramel Popcorn Day coming in on the 7th, and Jelly Bean Day happening on the 22nd. Make sure to carry around the mints and parsley on the morning of the 20th though, because the day before on the 19th is "National Garlic Day."
"Big Wind Day" on the 12th... "International Day of Laughter" on the 14th... and "Titanic Remembrance Day" for the 15th. Of course... you might want to Plan Your Own Epitaph on the 6th ..., maybe Walk Around Things on the 7th... and even Look Up At The Sky on the 14th.
All sound a little too crazy for you...? Nah... crazy is happening on the 15th when the world celebrates "Rubber Eraser Day".
April... the Month of Humor. Laughter releases endorphins, the body's feel-good chemical. They say laughter is the best medicine. April is also Stress Awareness Month. So go on then... release some of that stress with a right old laugh. Err... did I mention Cheeseball Day on the 17th...?