Updates documentation

Author: sdispater

docs/index.rst

@@ -636,7 +636,7 @@ the ``now()`` is created in the same timezone as the instance.
     born = pendulum.from_date(1987, 4, 23)
     not_birthday = pendulum.from_date(2014, 9, 26)
     birthday = pendulum.from_date(2014, 2, 23)
-    past_birthday = pendulum.now().sub(years=50)
+    past_birthday = pendulum.now().subtract(years=50)
 
     born.is_birthday(not_birthday)
     False
@@ -650,8 +650,8 @@ the ``now()`` is created in the same timezone as the instance.
 Addition and Subtraction
 ========================
 
-To easily adding and subtracting time, you can use the ``add()`` and ``sub()``
-methods`.
+To easily adding and subtracting time, you can use the ``add()`` and ``subtract()``
+methods.
 Each method returns a new ``Pendulum`` instance.
 
 .. code-block:: python
@@ -667,68 +667,68 @@ Each method returns a new ``Pendulum`` instance.
     '2017-01-31 00:00:00'
     dt = dt.add(years=1)
     '2018-01-31 00:00:00'
-    dt = dt.sub(years=1)
+    dt = dt.subtract(years=1)
     '2017-01-31 00:00:00'
-    dt = dt.sub(years=5)
+    dt = dt.subtract(years=5)
     '2012-01-31 00:00:00'
 
     dt = dt.add(months=60)
     '2017-01-31 00:00:00'
     dt = dt.add(months=1)
     '2017-02-28 00:00:00'
-    dt = dt.sub(months=1)
+    dt = dt.subtract(months=1)
     '2017-01-28 00:00:00'
-    dt = dt.sub(months=60)
+    dt = dt.subtract(months=60)
     '2012-01-28 00:00:00'
 
     dt = dt.add(days=29)
     '2012-02-26 00:00:00'
     dt = dt.add(days=1)
     '2012-02-27 00:00:00'
-    dt = dt.sub(days=1)
+    dt = dt.subtract(days=1)
     '2012-02-26 00:00:00'
-    dt = dt.sub(days=29)
+    dt = dt.subtract(days=29)
     '2012-01-28 00:00:00'
 
     dt = dt.add(weeks=3)
     '2012-02-18 00:00:00'
     dt = dt.add(weeks=1)
     '2012-02-25 00:00:00'
-    dt = dt.sub(weeks=1)
+    dt = dt.subtract(weeks=1)
     '2012-02-18 00:00:00'
-    dt = dt.sub(weeks=3)
+    dt = dt.subtract(weeks=3)
     '2012-01-28 00:00:00'
 
     dt = dt.add(hours=24)
     '2012-01-29 00:00:00'
     dt = dt.add(hours=1)
     '2012-02-25 01:00:00'
-    dt = dt.sub(hours=1)
+    dt = dt.subtract(hours=1)
     '2012-02-29 00:00:00'
-    dt = dt.sub(hours=24)
+    dt = dt.subtract(hours=24)
     '2012-01-28 00:00:00'
 
     dt = dt.add(minutes=61)
     '2012-01-28 01:01:00'
     dt = dt.add(minutes=1)
     '2012-01-28 01:02:00'
-    dt = dt.sub(minutes=1)
+    dt = dt.subtract(minutes=1)
     '2012-01-28 01:01:00'
-    dt = dt.sub(minutes=24)
+    dt = dt.subtract(minutes=24)
     '2012-01-28 00:00:00'
 
     dt = dt.add(seconds=61)
     '2012-01-28 00:01:01'
     dt = dt.add(seconds=1)
     '2012-01-28 00:01:02'
-    dt = dt.sub(seconds=1)
+    dt = dt.subtract(seconds=1)
     '2012-01-28 00:01:01'
-    dt = dt.sub(seconds=61)
+    dt = dt.subtract(seconds=61)
     '2012-01-28 00:00:00'
 
     dt = dt.add(years=3, months=2, days=6, hours=12, minutes=31, seconds=43)
     '2015-04-03 12:31:43'
-    dt = dt.sub(years=3, months=2, days=6, hours=12, minutes=31, seconds=43)
+    dt = dt.subtract(years=3, months=2, days=6, hours=12, minutes=31, seconds=43)
     '2012-01-28 00:00:00'
 
     # You can also add or remove a timedelta
@@ -737,6 +737,11 @@ Each method returns a new ``Pendulum`` instance.
     dt.sub_timedelta(timedelta(hours=3, minutes=4, seconds=5))
     '2012-01-28 00:00:00'
 
+.. note::
+
+    Passing negative values to ``add()`` is also possible and will act exactly
+    like ``subtract()``
+
 
 Difference
 ==========
@@ -770,7 +775,7 @@ This will default to ``True``, return the absolute value. The comparisons are do
     dt = pendulum.create(2012, 1, 31, 0)
     dt.diff(dt.add(months=1)).in_days()
     29
-    dt.diff(dt.sub(months=1), False).in_days()
+    dt.diff(dt.subtract(months=1), False).in_days()
     -31
 
     dt = pendulum.create(2012, 4, 30, 0)
@@ -823,25 +828,25 @@ You may also pass ``True`` as a 2nd parameter to remove the modifiers `ago`, `fr
     # The most typical usage is for comments
     # The instance is the date the comment was created
     # and its being compared to default now()
-    pendulum.now().sub(dayss=1).diff_for_humans()
+    pendulum.now().subtract(dayss=1).diff_for_humans()
     '5 days ago'
 
-    pendulum.now().diff_for_humans(Pendulum.now().sub(years=1))
+    pendulum.now().diff_for_humans(Pendulum.now().subtract(years=1))
     '1 year after'
 
     dt = pendulum.from_date(2011, 8, 1)
     dt.diff_for_humans(dt.add(months=1))
     '1 month before'
-    dt.diff_for_humans(dt.sub(months=1))
+    dt.diff_for_humans(dt.subtract(months=1))
     '1 month after'
 
     pendulum.now().add(seconds=5).diff_for_humans()
     '5 seconds from now'
 
-    pendulum.now().sub(days=24).diff_for_humans()
+    pendulum.now().subtract(days=24).diff_for_humans()
     '3 weeks ago'
 
-    pendulum.now().sub(days=24).diff_for_humans(absolute=True)
+    pendulum.now().subtract(days=24).diff_for_humans(absolute=True)
     '3 weeks'
 
 You can also change the locale of the string either globally by using ``pendulum.set_locale('fr')``