1 files changed, 34 insertions, 16 deletions
diff --git a/bot/converters.py b/bot/converters.py
index 7386187ab..339da7b60 100644
--- a/bot/converters.py
+++ b/bot/converters.py
@@ -1,11 +1,12 @@
 import logging
+import re
 from datetime import datetime
 from ssl import CertificateError
 from typing import Union
 
-import dateparser
 import discord
 from aiohttp import ClientConnectorError
+from dateutil.relativedelta import relativedelta
 from discord.ext.commands import BadArgument, Context, Converter
 
 
@@ -177,23 +178,40 @@ class TagContentConverter(Converter):
         return tag_content
 
 
-class ExpirationDate(Converter):
-    """Convert relative expiration date into UTC datetime using dateparser."""
+class Duration(Converter):
+    """Convert duration strings into UTC datetime.datetime objects."""
 
-    DATEPARSER_SETTINGS = {
-        'PREFER_DATES_FROM': 'future',
-        'TIMEZONE': 'UTC',
-        'TO_TIMEZONE': 'UTC'
-    }
+    duration_parser = re.compile(
+        r"((?P<years>\d+?) ?(years|year|Y|y) ?)?"
+        r"((?P<months>\d+?) ?(months|month|m) ?)?"
+        r"((?P<weeks>\d+?) ?(weeks|week|W|w) ?)?"
+        r"((?P<days>\d+?) ?(days|day|D|d) ?)?"
+        r"((?P<hours>\d+?) ?(hours|hour|H|h) ?)?"
+        r"((?P<minutes>\d+?) ?(minutes|minute|M) ?)?"
+        r"((?P<seconds>\d+?) ?(seconds|second|S|s))?"
+    )
 
-    async def convert(self, ctx: Context, expiration_string: str) -> datetime:
-        """Convert relative expiration date into UTC datetime."""
-        expiry = dateparser.parse(expiration_string, settings=self.DATEPARSER_SETTINGS)
-        if expiry is None:
-            raise BadArgument(f"Failed to parse expiration date from `{expiration_string}`")
+    async def convert(self, ctx: Context, duration: str) -> datetime:
+        """
+        Converts a `duration` string to a datetime object that's `duration` in the future.
+
+        The converter supports the following symbols for each unit of time:
+        - years: `Y`, `y`, `year`, `years`
+        - months: `m`, `month`, `months`
+        - weeks: `w`, `W`, `week`, `weeks`
+        - days: `d`, `D`, `day`, `days`
+        - hours: `H`, `h`, `hour`, `hours`
+        - minutes: `M`, `minute`, `minutes`
+        - seconds: `S`, `s`, `second`, `seconds`
+
+        The units need to be provided in descending order of magnitude.
+        """
+        match = self.duration_parser.fullmatch(duration)
+        if not match:
+            raise BadArgument(f"`{duration}` is not a valid duration string.")
 
+        duration_dict = {unit: int(amount) for unit, amount in match.groupdict(default=0).items()}
+        delta = relativedelta(**duration_dict)
         now = datetime.utcnow()
-        if expiry < now:
-            expiry = now + (now - expiry)
 
-        return expiry
+        return now + delta