diff --git a/maya/core.py b/maya/core.py
index d1b25a0..d2fb23b 100644
--- a/maya/core.py
+++ b/maya/core.py
@@ -675,7 +675,7 @@ def now():
     return MayaDT(epoch=epoch)
 
 
-def when(string, timezone='UTC', prefer_past=False):
+def when(string, timezone='UTC', prefer_dates_from='current_period'):
     """"Returns a MayaDT instance for the human moment specified.
 
     Powered by dateparser. Useful for scraping websites.
@@ -686,16 +686,20 @@ def when(string, timezone='UTC', prefer_past=False):
     Keyword Arguments:
         string -- string to be parsed
         timezone -- timezone referenced from (default: 'UTC')
-        prefer_past -- prefer parsing ambiguous date as in the past
+        prefer_dates_from -- what dates are prefered when `string` is ambigous.
+                             options are 'past', 'future', and 'current_period'
+                             (default: 'current_period'). see: [1]
 
+    Reference:
+        [1] dateparser.readthedocs.io/en/latest/usage.html#handling-incomplete-dates
     """
     settings = {
         'TIMEZONE': timezone,
         'RETURN_AS_TIMEZONE_AWARE': True,
         'TO_TIMEZONE': 'UTC',
+        'PREFER_DATES_FROM': prefer_dates_from,
     }
-    if prefer_past:
-        settings['PREFER_DATES_FROM'] = 'past'
+
     dt = dateparser.parse(string, settings=settings)
     if dt is None:
         raise ValueError('invalid datetime input specified.')
diff --git a/tests/test_maya.py b/tests/test_maya.py
index b926d6f..dd8e361 100644
--- a/tests/test_maya.py
+++ b/tests/test_maya.py
@@ -1,5 +1,6 @@
 import copy
 import time
+import calendar
 from datetime import timedelta, datetime as Datetime
 
 import pytz
@@ -191,16 +192,46 @@ def test_parse(string, kwds, expected):
 
 @pytest.mark.usefixtures("frozen_now")
 def test_when_past():
-    next_month = str(maya.now().add(months=1).month)
-    this_year = maya.now().year
-    last_year = this_year - 1
-    future_date = maya.when(next_month)
-    past_date = maya.when(next_month, prefer_past=True)
-    assert future_date.year == this_year
-    if next_month == '1':
-        assert past_date.year == this_year
-    else:
-        assert past_date.year == last_year
+    two_days_away = maya.now().add(days=2)
+
+    past_date = maya.when(
+            two_days_away.slang_date(),
+            prefer_dates_from='past')
+
+    assert past_date < maya.now()
+
+
+@pytest.mark.usefixtures("frozen_now")
+def test_when_future():
+    two_days_away = maya.now().add(days=2)
+
+    future_date = maya.when(
+            two_days_away.slang_date(),
+            prefer_dates_from='future')
+
+    assert future_date > maya.now()
+
+
+@pytest.mark.usefixtures("frozen_now")
+def test_when_past_day_name():
+    two_days_away = maya.now().add(days=2)
+
+    past_date = maya.when(
+            calendar.day_name[two_days_away.weekday],
+            prefer_dates_from='past')
+
+    assert past_date < maya.now()
+
+
+@pytest.mark.usefixtures("frozen_now")
+def test_when_future_day_name():
+    two_days_away = maya.now().add(days=2)
+
+    future_date = maya.when(
+            calendar.day_name[two_days_away.weekday],
+            prefer_dates_from='future')
+
+    assert future_date > maya.now()
 
 
 def test_datetime_to_timezone():