diff --git a/aoc/src/lib.rs b/aoc/src/lib.rs
index 16b7871..bd6c1e7 100644
--- a/aoc/src/lib.rs
+++ b/aoc/src/lib.rs
@@ -1,6 +1,32 @@
+use std::env;
+
 pub type Result<T> = std::result::Result<T, Box<dyn std::error::Error>>;
 
 #[macro_export]
 macro_rules! err {
     ($($string:expr),+) => (Box::<dyn std::error::Error>::from(format!($($string),+)))
 }
+
+type DayFunc = fn() -> Result<()>;
+
+pub fn run(days: &[DayFunc]) -> Result<()> {
+    let mut args = env::args();
+    args.next();
+
+    match args.next() {
+        Some(arg) => {
+            let day: usize = arg.parse().expect("Please provide a day number");
+            days[day - 1]().unwrap_or_else(|e| eprintln!("error running day specified: {}", e));
+        }
+        None => {
+            for (i, day) in days.iter().enumerate() {
+                let i = i + 1;
+                println!("day{}: ", i);
+                day().unwrap_or_else(|e| eprintln!("error running day {}: {}", i, e));
+                println!();
+            }
+        }
+    }
+
+    Ok(())
+}
diff --git a/aoc2015/src/main.rs b/aoc2015/src/main.rs
index 525cc22..4fc407f 100644
--- a/aoc2015/src/main.rs
+++ b/aoc2015/src/main.rs
@@ -1,5 +1,3 @@
-use std::env;
-
 use aoc::Result;
 
 use aoc2015::day01;
@@ -7,23 +5,5 @@ use aoc2015::day01;
 fn main() -> Result<()> {
     let days: &[fn() -> Result<()>] = &[day01::run];
 
-    let mut args = env::args();
-    args.next();
-
-    match args.next() {
-        Some(arg) => {
-            let day: usize = arg.parse().expect("Please provide a day number");
-            days[day - 1]().unwrap_or_else(|e| eprintln!("error running day specified: {}", e));
-        }
-        None => {
-            for (i, day) in days.iter().enumerate() {
-                let i = i + 1;
-                println!("day{}: ", i);
-                day().unwrap_or_else(|e| eprintln!("error running day {}: {}", i, e));
-                println!();
-            }
-        }
-    }
-
-    Ok(())
+    aoc::run(days)
 }
diff --git a/aoc2018/src/main.rs b/aoc2018/src/main.rs
index 7d72540..5aaf2e6 100644
--- a/aoc2018/src/main.rs
+++ b/aoc2018/src/main.rs
@@ -1,5 +1,3 @@
-use std::env;
-
 use aoc::Result;
 
 use aoc2018::day01;
@@ -11,23 +9,5 @@ use aoc2018::day05;
 fn main() -> Result<()> {
     let days: &[fn() -> Result<()>] = &[day01::run, day02::run, day03::run, day04::run, day05::run];
 
-    let mut args = env::args();
-    args.next();
-
-    match args.next() {
-        Some(arg) => {
-            let day: usize = arg.parse().expect("Please provide a day number");
-            days[day - 1]().unwrap_or_else(|e| eprintln!("error running day specified: {}", e));
-        }
-        None => {
-            for (i, day) in days.iter().enumerate() {
-                let i = i + 1;
-                println!("day{}: ", i);
-                day().unwrap_or_else(|e| eprintln!("error running day {}: {}", i, e));
-                println!();
-            }
-        }
-    }
-
-    Ok(())
+    aoc::run(days)
 }
diff --git a/aoc2019/src/main.rs b/aoc2019/src/main.rs
index a67a3e5..c841d6c 100644
--- a/aoc2019/src/main.rs
+++ b/aoc2019/src/main.rs
@@ -1,30 +1,10 @@
-use std::env;
+use aoc::Result;
 
 use aoc2019::day01;
 use aoc2019::day02;
 
-use aoc2019::Result;
-
 fn main() -> Result<()> {
     let days: &[fn() -> Result<()>] = &[day01::run, day02::run];
 
-    let mut args = env::args();
-    args.next();
-
-    match args.next() {
-        Some(arg) => {
-            let day: usize = arg.parse().expect("Please provide a day number");
-            days[day - 1]().unwrap_or_else(|e| eprintln!("error running day specified: {}", e));
-        }
-        None => {
-            for (i, day) in days.iter().enumerate() {
-                let i = i + 1;
-                println!("day{}: ", i);
-                day().unwrap_or_else(|e| eprintln!("error running day {}: {}", i, e));
-                println!();
-            }
-        }
-    }
-
-    Ok(())
+    aoc::run(days)
 }