diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..e69de29
diff --git a/README.markdown b/README.markdown
index 7220c9f..d677ce5 100644
--- a/README.markdown
+++ b/README.markdown
@@ -2,6 +2,11 @@
 
 As it was suggested on issue [#28](https://github.com/freitass/todo.txt-vim/issues/28) (and as recommended by vim's documentation), all mappings were changed to use `<localleader>` instead of `<leader>`. If you don't have `maplocalleader` set on your environment then yours is probably `\`. For more information on that regard, please take a look at `:h <Localleader>`.
 
+### (Jan 2016) Note: Overdue date highlight and Python Optional dependency
+
+A new feature was added to highlight dates in overdue tasks as an Error (as suggested on issue [#44][https://github.com/freitass/todo.txt-vim/issues/44]). It depends on a Python library, however, and as such will only be able to work if your version of Vim was compiled with the `+python` option (as most common versions do).
+
+If your Vim installation does **not** have Python support, this plugin **will work just fine** but this feature will be disabled.
 
 ### Quick install
 
@@ -17,6 +22,7 @@ Sorting tasks:
 `<localleader>s+`  Sort the file on +Projects  
 `<localleader>s@`  Sort the file on @Contexts  
 `<localleader>sd`  Sort the file on dates  
+`<localleader>sdd`  Sort the file on due dates  
 
 Edit priority:  
 `<localleader>j`   Decrease the priority of the current line  
diff --git a/syntax/python/dateregex/dateregex/__init__.py b/syntax/python/dateregex/dateregex/__init__.py
new file mode 100644
index 0000000..cfbc141
--- /dev/null
+++ b/syntax/python/dateregex/dateregex/__init__.py
@@ -0,0 +1,11 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# File:        __init__.py
+# Author:      Guilherme Victal <guilherme at victal.eti.br>
+# Description: Dateregex library entry point
+# License:     Vim license
+# Website:     http://github.com/freitass/todo.txt-vim
+# Version:     0.1
+
+from after import regex_date_after
+from before import regex_date_before
diff --git a/syntax/python/dateregex/dateregex/after.py b/syntax/python/dateregex/dateregex/after.py
new file mode 100644
index 0000000..8a13574
--- /dev/null
+++ b/syntax/python/dateregex/dateregex/after.py
@@ -0,0 +1,95 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# File:        after.py
+# Author:      Guilherme Victal <guilherme at victal.eti.br>
+# Description: Generates regexes after a certain date
+# License:     Vim license
+# Website:     http://github.com/freitass/todo.txt-vim
+# Version:     0.1
+
+from datetime import date, timedelta, MAXYEAR
+
+
+def _year_regex_after(year):
+    if int(year) > MAXYEAR:
+        return None
+
+    year_regex = r'(\d+\d{%s}' % len(year)
+    for idx, digit in enumerate(year):
+        if digit != '9':
+            regex = '|' + year[0:idx]
+            regex += '9' if digit == '8' else '[%s-9]' % str(int(digit) + 1)
+            if idx < len(year) - 1:
+                regex += '\d{%s}' % (len(year) - (idx + 1)) 
+            year_regex += regex
+
+    year_regex += ')'
+    return '-'.join((year_regex, r'\d{2}', r'\d{2}'))
+
+
+def _month_regex_after(year, month):
+    if month == '12':
+        return None
+
+    digit1, digit2 = month
+    if digit1 == '1':
+        month_regex = r'12' if month == '11' else r'1[12]'
+    else:
+        month_regex = r'1[0-2]'
+        if digit2 != '9':
+            if digit2 == '8':
+                month_regex = r'(' + month_regex + r'|09)'
+            else:
+                month_regex = r'(' + month_regex + r'|0[%s-9])' 
+                month_regex = month_regex % str(int(digit2) + 1)
+    return '-'.join((year, month_regex, r'\d{2}'))
+
+def _day_regex_after(year, month, day):
+    last_month_day = str((date(int(year), (int(month) + 1) % 12, 1) + - date.resolution).day)
+    if day == last_month_day:
+        return None
+    day_regex = r'('
+    digit1, digit2 = day
+    last_digit1, last_digit2 = last_month_day
+    if digit1 == last_digit1:
+        day_regex = last_month_day if int(digit2) == int(last_digit2) - 1 else last_digit1 + r'[%s-%s]' % (str(int(digit2) + 1), last_digit2)
+    else:
+        day_regex = r'('
+        day_regex += last_digit1 if int(digit1) == int(last_digit1) - 1 else r'[%s-%s]' % (str(int(digit1) + 1), last_digit1)
+        day_regex +=r'\d'
+        if digit2 < '9':
+            day_regex += '|' + digit1
+            day_regex += '9' if digit2 == '8' else r'[%s-9]' % str(int(digit2) + 1)
+
+        day_regex += ')'
+    return '-'.join((year, month, day_regex))
+
+
+def regex_date_after(given_date):
+    year, month, day = given_date.isoformat().split('-')
+
+    year_regex = _year_regex_after(year)
+    month_regex = _month_regex_after(year, month)
+    day_regex = _day_regex_after(year, month, day)
+
+    date_regex = '(' + year_regex if year_regex else '('
+    date_regex += ('|' + month_regex) if month_regex else ''
+    date_regex += ('|' + day_regex) if day_regex else ''
+    date_regex += ')'
+    return date_regex
+
+
+def __main():
+    import re
+    date_regex = regex_date_after(date(1999,12,31))
+    print(date_regex)
+    pattern = re.compile(date_regex)
+
+
+    d = date.today() + date.resolution
+    assert pattern.match(date.strftime(d, '%Y-%m-%d')) is not None
+    print(date.strftime(d, '%Y-%m-%d') + ' is okay')
+    d += date.resolution
+
+if __name__ == '__main__':
+    __main()
diff --git a/syntax/python/dateregex/dateregex/before.py b/syntax/python/dateregex/dateregex/before.py
new file mode 100644
index 0000000..8a3402e
--- /dev/null
+++ b/syntax/python/dateregex/dateregex/before.py
@@ -0,0 +1,79 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# File:        before.py
+# Author:      Guilherme Victal <guilherme at victal.eti.br>
+# Description: Generates regexes before a certain date
+# License:     Vim license
+# Website:     http://github.com/freitass/todo.txt-vim
+# Version:     0.1
+
+from datetime import date, timedelta, MINYEAR
+
+def _year_regex_before(year):
+    if int(year) <= MINYEAR: 
+        return None
+    year_regex = r'('
+    year_regex += r'\d{1,%s}' % str(len(year) - 1) if len(year) > 1 else ''
+    for idx, digit in enumerate(year):
+        if digit != '0':
+            regex = '|' + year[0:idx]
+            regex += '0' if digit == '1' else '[0-%s]' % str(int(digit) - 1)
+            if idx < len(year) - 1:
+                regex += '\d{%s}' % (len(year) - (idx + 1)) 
+            year_regex += regex
+
+    year_regex += ')'
+    return '-'.join((year_regex, r'\d{2}', r'\d{2}'))
+    
+def _month_regex_before(year, month):
+    if month == '01':
+        return None
+
+    digit1, digit2 = month
+    if digit1 == '0':
+        month_regex = '01' if month == '02' else r'0[1-%s]' % str(int(digit2) - 1)
+    elif month == '10':
+        month_regex = r'0\d' 
+    elif month == '11':
+        month_regex = r'(0\d|10)'
+    else:
+        month_regex = r'(0\d|1[01])'
+
+    return '-'.join((year, month_regex, r'\d{2}'))
+
+def _day_regex_before(year, month, day):
+    if day == '01':
+        return None
+    last_month_day = str((date(int(year), (int(month) + 1) % 12, 1) + - date.resolution).day)
+    last_digit1, last_digit2 = last_month_day
+
+    digit1, digit2 = day
+    if digit1 == '0':
+        day_regex = '01' if day == '02' else r'0[1-%s]' % str(int(digit2) - 1)
+    else:
+        day_regex = r'('
+        day_regex += '0' if digit1 == '1' else r'[0-%s]' % str(int(digit1) - 1)
+        day_regex += r'\d'
+        if digit2 != '0':
+            day_regex += '|'
+            day_regex += digit1
+            day_regex += '0' if digit2 == '1' else r'[0-%s]' % str(int(digit2) - 1)
+        day_regex += ')'
+
+    return '-'.join((year, month, day_regex))
+
+
+    
+
+def regex_date_before(given_date):
+    year, month, day = given_date.isoformat().split('-')
+
+    year_regex = _year_regex_before(year)
+    month_regex = _month_regex_before(year, month)
+    day_regex = _day_regex_before(year, month, day)
+
+    date_regex = '(' + year_regex if year_regex else '('
+    date_regex += ('|' + month_regex) if month_regex else ''
+    date_regex += ('|' + day_regex) if day_regex else ''
+    date_regex += ')'
+    return date_regex
diff --git a/syntax/python/todo.py b/syntax/python/todo.py
new file mode 100644
index 0000000..36d0d9d
--- /dev/null
+++ b/syntax/python/todo.py
@@ -0,0 +1,31 @@
+#!/usr/bin/env python2
+# -*- coding: utf-8 -*-
+# File:        todo.py
+# Description: Todo.txt overdue date syntax script
+# License:     Vim license
+# Website:     http://github.com/freitass/todo.txt-vim
+# Version:     0.1
+
+import vim
+import os
+import sys
+from datetime import date
+
+dateregex_dir = os.path.join(vim.eval('s:script_dir'), 'dateregex')
+if os.path.isdir(dateregex_dir):
+    sys.path.insert(0, dateregex_dir)
+
+def add_due_date_syntax_highlight():
+    try: 
+        from dateregex import regex_date_before
+    except ImportError:
+        print("dateregex module not found. Overdue dates won't be highlighted")
+        return 
+
+    regex = regex_date_before(date.today())
+    regex = r'(^|<)due:%s(>|$)' % regex
+
+    vim.command("syntax match OverDueDate '\\v%s'" % regex)
+    vim.command("highlight  default  link  OverDueDate       Error")
+
+add_due_date_syntax_highlight()
diff --git a/syntax/todo.vim b/syntax/todo.vim
index eabcd9f..f7c5105 100644
--- a/syntax/todo.vim
+++ b/syntax/todo.vim
@@ -9,33 +9,34 @@ if exists("b:current_syntax")
     finish
 endif
 
-syntax  match  TodoDone       '^[xX]\s.\+$'               contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityA  '^([aA])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityB  '^([bB])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityC  '^([cC])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityD  '^([dD])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityE  '^([eE])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityF  '^([fF])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityG  '^([gG])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityH  '^([hH])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityI  '^([iI])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityJ  '^([jJ])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityK  '^([kK])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityL  '^([lL])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityM  '^([mM])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityN  '^([nN])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityO  '^([oO])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityP  '^([pP])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityQ  '^([qQ])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityR  '^([rR])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityS  '^([sS])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityT  '^([tT])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityU  '^([uU])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityV  '^([vV])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityW  '^([wW])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityX  '^([xX])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityY  '^([yY])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
-syntax  match  TodoPriorityZ  '^([zZ])\s.\+$'             contains=TodoDate,TodoProject,TodoContext
+syntax  match  TodoDone       '^[xX]\s.\+$'               contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityA  '^([aA])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityB  '^([bB])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityC  '^([cC])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityD  '^([dD])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityE  '^([eE])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityF  '^([fF])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityG  '^([gG])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityH  '^([hH])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityI  '^([iI])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityJ  '^([jJ])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityK  '^([kK])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityL  '^([lL])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityM  '^([mM])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityN  '^([nN])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityO  '^([oO])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityP  '^([pP])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityQ  '^([qQ])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityR  '^([rR])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityS  '^([sS])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityT  '^([tT])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityU  '^([uU])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityV  '^([vV])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityW  '^([wW])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityX  '^([xX])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityY  '^([yY])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+syntax  match  TodoPriorityZ  '^([zZ])\s.\+$'             contains=TodoDate,TodoProject,TodoContext,OverDueDate
+
 syntax  match  TodoDate       '\d\{2,4\}-\d\{2\}-\d\{2\}' contains=NONE
 syntax  match  TodoProject    '\(^\|\W\)+[^[:blank:]]\+'  contains=NONE
 syntax  match  TodoContext    '\(^\|\W\)@[^[:blank:]]\+'  contains=NONE
@@ -49,4 +50,12 @@ highlight  default  link  TodoDate       PreProc
 highlight  default  link  TodoProject    Special
 highlight  default  link  TodoContext    Special
 
+if has('python')
+    let b:curdir = expand('<sfile>:p:h')
+    let s:script_dir = b:curdir . "/python/"
+    execute "pyfile " . s:script_dir. "todo.py"
+else
+    echom "Your version of vim has no python support. Overdue dates won't be highlighted"
+endif
+
 let b:current_syntax = "todo"