diff --git a/darc/archive.py b/darc/archive.py
index c4d1698ac..3707d2f69 100644
--- a/darc/archive.py
+++ b/darc/archive.py
@@ -43,7 +43,9 @@ class Archive(object):
         except self.store.DoesNotExist:
             raise self.DoesNotExist
         self.metadata = msgpack.unpackb(data)
-        assert self.metadata['version'] == 1
+        if self.metadata['version'] != 1:
+            raise Exception('Unknown archive metadata version')
+        self.name = self.metadata['name']
 
     @property
     def ts(self):
diff --git a/darc/archiver.py b/darc/archiver.py
index 19dde8dde..2c538135f 100644
--- a/darc/archiver.py
+++ b/darc/archiver.py
@@ -11,7 +11,7 @@ from .cache import Cache
 from .key import Key
 from .helpers import location_validator, format_file_size, format_time,\
     format_file_mode, IncludePattern, ExcludePattern, exclude_path, to_localtime, \
-    get_cache_dir
+    get_cache_dir, day_of_year
 from .remote import StoreServer, RemoteStore
 
 class Archiver(object):
@@ -224,31 +224,39 @@ class Archiver(object):
         num_daily = args.daily
         num_weekly = args.weekly
         num_monthly = args.monthly
-        if args.daily + args.weekly + args.monthly == 0:
-            self.print_error('At least one of the "daily", "weekly", "monthly" '
+        num_yearly = args.yearly
+        if args.daily + args.weekly + args.monthly + args.yearly == 0:
+            self.print_error('At least one of the "daily", "weekly", "monthly" or "yearly" '
                              'settings must be specified')
             return 1
         t0 = date.today() + timedelta(days=1) # Tomorrow
-        daily = weekly = monthly = 0
+        daily = weekly = monthly = yearly = 0
         for archive in archives:
+            if args.prefix and not archive.name.startswith(args.prefix):
+                continue
             t = to_localtime(archive.ts).date()
             if daily < args.daily and t < t0:
                 daily += 1
                 self.print_verbose('Archive "%s" is daily archive number %d',
-                                   archive.metadata['name'], daily)
+                                   archive.name, daily)
                 t0 = t
             elif weekly < args.weekly and t < t0 and t.weekday() == 1:
                 weekly += 1
                 self.print_verbose('Archive "%s" is weekly archive number %d',
-                                   archive.metadata['name'], weekly)
+                                   archive.name, weekly)
                 t0 = t
             elif monthly < args.monthly and t < t0 and t.day == 1:
-                num_weekly += 1
+                monthly += 1
                 self.print_verbose('Archive "%s" is monthly archive number %d',
-                                   archive.metadata['name'], monthly)
+                                   archive.name, monthly)
+                t0 = t
+            elif yearly < args.yearly and t < t0 and day_of_year(t) == 1:
+                yearly += 1
+                self.print_verbose('Archive "%s" is yearly archive number %d',
+                                   archive.name, yearly)
                 t0 = t
             else:
-                self.print_verbose('Purging archive %s', archive.metadata['name'])
+                self.print_verbose('Purging archive %s', archive.name)
                 if args.really:
                     archive.delete(cache)
                 else:
@@ -346,6 +354,10 @@ class Archiver(object):
                                help='Number of daily archives to keep')
         subparser.add_argument('-m', '--monthly', dest='monthly', type=int, default=0,
                                help='Number of monthly archives to keep')
+        subparser.add_argument('-y', '--yearly', dest='yearly', type=int, default=0,
+                               help='Number of yearly archives to keep')
+        subparser.add_argument('-p', '--prefix', dest='prefix', type=str,
+                               help='Only consider archive names starting with this prefix')
         subparser.add_argument('-r', '--really', dest='really',
                                action='store_true', default=False,
                                help='Actually delete archives')
diff --git a/darc/helpers.py b/darc/helpers.py
index 0ad9953eb..06a6dfea7 100644
--- a/darc/helpers.py
+++ b/darc/helpers.py
@@ -12,6 +12,12 @@ import sys
 import time
 import urllib
 
+
+def day_of_year(d):
+    """Calculate the "day of year" from a date object"""
+    return int(d.strftime('%j'))
+
+
 # OSX filenames are UTF-8 Only so any non-utf8 filenames are url encoded
 if sys.platform == 'darwin':
     def encode_filename(name):
@@ -23,6 +29,7 @@ if sys.platform == 'darwin':
 else:
     encode_filename = str
 
+
 class Counter(object):
 
     __slots__ = ('v',)
@@ -48,6 +55,7 @@ def get_keys_dir():
     return os.environ.get('DARC_KEYS_DIR',
                           os.path.join(os.path.expanduser('~'), '.darc', 'keys'))
 
+
 def get_cache_dir():
     """Determine where to store keys and cache"""
     return os.environ.get('DARC_CACHE_DIR',
@@ -69,14 +77,17 @@ def deferrable(f):
             return f(*args, **kw)
     return wrapper
 
+
 def error_callback(res, error, data):
     if res:
         raise res
 
+
 def to_localtime(ts):
     """Convert datetime object from UTC to local time zone"""
     return ts - timedelta(seconds=time.altzone)
 
+
 def read_set(path):
     """Read set from disk (as int32s)
     """