diff --git a/adventofcode/aoc.py b/adventofcode/aoc.py
index 1149618..5750be0 100644
--- a/adventofcode/aoc.py
+++ b/adventofcode/aoc.py
@@ -1,21 +1,49 @@
 import argparse
 from pathlib import Path
-from adventofcode.helper import run, get_input_file, get_auth
 
+from adventofcode.helper import (
+    MAX_YEAR,
+    MIN_YEAR,
+    get_auth,
+    get_input_file,
+    get_max_day,
+    run,
+    run_all,
+)
 
 TEMPLATE = """#!/usr/bin/env python3
+import fileinput
+
+
 def main(inp):
     for l in inp:
         print(l)
 
 
 if __name__ == '__main__':
-    import fileinput
     lines = [x.rstrip() for x in fileinput.input()]
     main(lines)
 """
 
 
+def year_or_all(value):
+    """Custom type function to validate 'year' as either an integer or 'all'."""
+    if value.lower() == "all":
+        return value
+    try:
+        year = int(value)
+        if 2015 <= year <= 2025:
+            return year
+        else:
+            raise argparse.ArgumentTypeError(
+                f"Year must be between 2015 and 2025. Got: {year}"
+            )
+    except ValueError:
+        raise argparse.ArgumentTypeError(
+            f"Invalid value: {value}. Must be an integer or 'all'."
+        )
+
+
 def main():
     parser = argparse.ArgumentParser(description="Advent of Code CLI")
     subparsers = parser.add_subparsers(dest="command")
@@ -25,13 +53,15 @@ def main():
     init_parser.add_argument("day", type=int)
 
     run_parser = subparsers.add_parser("run", help="Run an aoc day")
-    run_parser.add_argument("year", type=int)
+    run_parser.add_argument("year", type=year_or_all)
     run_parser.add_argument("day", type=int, nargs="?", default=None)
 
     args = parser.parse_args()
 
     if args.command == "init":
         handle_init(args.year, args.day)
+    elif args.command == "run" and args.year == "all":
+        handle_run_all()
     elif args.command == "run":
         handle_run(args.year, args.day)
     else:
@@ -39,8 +69,13 @@ def main():
 
 
 def handle_init(year, day):
-    if not 1 <= day <= 25:
-        print(f"Invalid day: {day}. Must be between 1 and 25.")
+    if not MIN_YEAR <= year <= MAX_YEAR:
+        print(f"Invalid year: {year}. Must be between {MIN_YEAR} and {MAX_YEAR}.")
+        return
+
+    max_day = get_max_day(year)
+    if not 1 <= day <= max_day:
+        print(f"Invalid day: {day}. Must be between 1 and {max_day}.")
         return
 
     root = Path(__file__).parent
@@ -69,5 +104,9 @@ def handle_run(year, day):
     run(year, day)
 
 
+def handle_run_all():
+    run_all()
+
+
 if __name__ == "__main__":
     main()
diff --git a/adventofcode/helper.py b/adventofcode/helper.py
index 6fce493..e2f255e 100644
--- a/adventofcode/helper.py
+++ b/adventofcode/helper.py
@@ -1,13 +1,21 @@
 #!/usr/bin/env python3
-import urllib.request
+import os
+import subprocess
 import sys
 import time
-import subprocess
-import os
+import urllib.request
 from pathlib import Path
 
+MIN_YEAR = 2015
+MAX_YEAR = 2025
 ROOTPATH = Path(os.path.dirname(os.path.realpath(__file__)))
 
+
+def get_max_day(year):
+    # starting with 2025, advent of code only has 12 days
+    return 25 if year < 2025 else 12
+
+
 _auth = None
 
 
@@ -54,11 +62,30 @@ def get_input_file(year, day):
     return res
 
 
+def resolve_paths(year, day):
+    path = ROOTPATH / Path(f"{year}/day{day}")
+    script_path = path / Path(f"day{day}.py")
+    input_path = path / Path("input.txt")
+    return script_path, input_path
+
+
+def run_all():
+    for year in range(2015, MAX_YEAR + 1):
+        print(f"Running year {year}")
+        run(year, None)
+
+
 def run(year, day):
+    if not MIN_YEAR <= year <= MAX_YEAR:
+        print(f"Invalid year {year}", file=sys.stderr)
+        exit(1)
+
     if day is not None:
-        path = ROOTPATH / Path(f"{year}/day{day}")
-        script_path = path / Path(f"day{day}.py")
-        input_path = path / Path("input.txt")
+        if not 1 <= day <= get_max_day(year):
+            print(f"Invalid day {day}", file=sys.stderr)
+            exit(1)
+
+        script_path, input_path = resolve_paths(year, day)
         if not script_path.exists():
             print(f"Invalid day {day}", file=sys.stderr)
             exit(1)
@@ -72,9 +99,7 @@ def run(year, day):
         run_day(script_path, input_path)
     else:
         for day in range(1, 26):
-            path = ROOTPATH / Path(f"{year}/day{day}")
-            script_path = path / Path(f"day{day}.py")
-            input_path = path / Path("input.txt")
+            script_path, input_path = resolve_paths(year, day)
             if script_path.exists():
                 if not input_path.exists():
                     print(f"- downloading input file {input_path}")