diff --git a/irclog.py b/irclog.py
index 8b5f154..ec7258a 100644
--- a/irclog.py
+++ b/irclog.py
@@ -26,6 +26,11 @@ messageConnectionClosed = object() # Signals that the connection was closed by e
 messageEOF = object() # Special object to signal the end of messages to Storage
 
 
+def get_month_str(ts = None):
+	dt = datetime.datetime.utcfromtimestamp(ts).replace(tzinfo = datetime.timezone.utc) if ts is not None else datetime.datetime.utcnow()
+	return dt.strftime('%Y-%m')
+
+
 class InvalidConfig(Exception):
 	'''Error in configuration file'''
 
@@ -578,8 +583,7 @@ class Storage:
 	def __init__(self, messageQueue, config):
 		self.messageQueue = messageQueue
 		self.config = config
-		self.files = {} # channel|None -> fileobj; None = general log for anything that wasn't recognised as a message for the channel log
-		self.active = True
+		self.files = {} # channel|None -> (filename, fileobj); None = general raw log
 
 	def update_config(self, config):
 		channelsOld = {channel['ircchannel'] for channel in self.config['channels'].values()}
@@ -589,34 +593,35 @@ class Storage:
 
 		for channel in channelsRemoved:
 			if channel in self.files:
-				self.files[channel].close()
+				self.files[channel][1].close()
 				del self.files[channel]
 
-		#TODO mkdir as required
-		#TODO month
-
-		for channel in self.config['channels'].values():
-			if channel['ircchannel'] not in self.files and channel['active']:
-				self.files[channel['ircchannel']] = open(os.path.join(self.config['storage']['path'], channel['ircchannel'], '2020-10.log'), 'a')
-
-		if None not in self.files:
-			self.files[None] = open(os.path.join(self.config['storage']['path'], 'general', '2020-10.log'), 'ab')
+	def ensure_file_open(self, time_, channel):
+		fn = f'{get_month_str(time_)}.log'
+		if channel in self.files and fn == self.files[channel][0]:
+			return
+		if channel in self.files:
+			self.files[channel][1].close()
+		dn = channel if channel is not None else 'general'
+		mode = 'a' if channel is not None else 'ab'
+		os.makedirs(os.path.join(self.config['storage']['path'], dn), exist_ok = True)
+		self.files[channel] = (fn, open(os.path.join(self.config['storage']['path'], dn, fn), mode))
 
 	async def run(self, loop, sigintEvent):
 		self.update_config(self.config) # Ensure that files are open etc.
-		#TODO Task to rotate log files at the beginning of a new month
+		flushExitEvent = asyncio.Event()
 		storageTask = asyncio.create_task(self.store_messages(sigintEvent))
-		flushTask = asyncio.create_task(self.flush_files())
+		flushTask = asyncio.create_task(self.flush_files(flushExitEvent))
 		await sigintEvent.wait()
 		self.logger.debug('Got SIGINT, waiting for remaining messages to be stored')
 		await storageTask # Wait until everything's stored
-		self.active = False
+		flushExitEvent.set()
 		self.logger.debug('Waiting for flush task')
 		await flushTask
 		self.close()
 
 	async def store_messages(self, sigintEvent):
-		while self.active:
+		while True:
 			self.logger.debug('Waiting for message')
 			res = await self.messageQueue.get()
 			self.logger.debug(f'Got {res!r} from message queue')
@@ -635,31 +640,25 @@ class Storage:
 			return
 
 		self.logger.debug(f'Logging {message!r} ({command}) at {time_} for {channel!r}')
-		if channel not in self.files:
-			self.logger.warning(f'Channel {channel!r} is not opened, dropping log message {message!r} ({command!r}) at {time_}')
-			return
+		self.ensure_file_open(time_, channel)
 		if channel is None:
-			self.files[None].write(str(time_).encode('ascii') + b' ' + message + b'\n')
+			self.files[None][1].write(str(time_).encode('ascii') + b' ' + message + b'\n')
 		else:
-			self.files[channel].write(f'{time_} {command} {message}\n')
+			self.files[channel][1].write(f'{time_} {command} {message}\n')
 
-	def decode_channel(self, time_, rawMessage, channel):
-		try:
-			if isinstance(channel, list):
-				return [c.decode('utf-8') for c in channel]
-			return channel.decode('utf-8')
-		except UnicodeDecodeError as e:
-			self.logger.warning(f'Failed to decode channel name {channel!r} from {rawMessage!r} at {time_}: {e!s}')
-			self.store_message(time_, rawMessage, None)
-			return None
-
-	async def flush_files(self):
-		while self.active:
-			await asyncio.sleep(1)
+	async def flush_files(self, flushExitEvent):
+		while True:
+			await asyncio.wait((flushExitEvent.wait(), asyncio.sleep(60)), return_when = asyncio.FIRST_COMPLETED)
+			self.logger.debug('Flushing files')
+			for _, f in self.files.values():
+				f.flush()
+			self.logger.debug('Flushing done')
+			if flushExitEvent.is_set():
+				break
 		self.logger.debug('Exiting flush_files')
 
 	def close(self):
-		for f in self.files.values():
+		for _, f in self.files.values():
 			f.close()
 		self.files = {}