Add configurable first day of the week

Fixes psss#293

Signed-off-by: Sandro Bonazzola <sbonazzo@redhat.com>

did/base.py

@@ -13,7 +13,6 @@
 from datetime import timedelta
 
 from dateutil.relativedelta import FR as FRIDAY
-from dateutil.relativedelta import MO as MONDAY
 from dateutil.relativedelta import relativedelta as delta
 
 from did import utils
@@ -125,6 +124,17 @@ def quarter(self):
                 f"Invalid quarter start '{month}', should be integer.")
         return month
 
+    @property
+    def week(self):
+        """ The first day of the week, 0 (Monday) by default"""
+        week = self.parser.get("general", "week", fallback=0)
+        try:
+            week = int(week) % 7
+        except ValueError as exc:
+            raise ConfigError(
+                f"Invalid week start '{week}', should be integer.") from exc
+        return week
+
     @property
     def email(self):
         """ User email(s) """
@@ -256,14 +266,18 @@ def __sub__(self, subtrahend):
     @staticmethod
     def this_week():
         """ Return start and end date of the current week. """
-        since = TODAY + delta(weekday=MONDAY(-1))
+        since = TODAY
+        while since.weekday() != Config().week:
+            since -= delta(days=1)
         until = since + delta(weeks=1)
         return Date(since), Date(until)
 
     @staticmethod
     def last_week():
         """ Return start and end date of the last week. """
-        since = TODAY + delta(weekday=MONDAY(-2))
+        since = TODAY - delta(weeks=1)
+        while since.weekday() != Config().week:
+            since -= delta(days=1)
         until = since + delta(weeks=1)
         return Date(since), Date(until)
 

docs/config.rst

@@ -26,13 +26,17 @@ Minimum config file should contain at least a ``general`` section
 with an email address which will be used for searching. Option
 ``width`` specifies the maximum width of the report, ``quarter``
 can be used to choose a different start month of the quarter.
+Option ``week`` can be used to choose a different first day of the week:
+defaults to ``0`` which is Monday;
+other common setting for this option would be ``6`` which is Sunday.
 The ``separator`` and ``separator_width`` options control the
 character used, and width of the separator between users::
 
     [general]
     email = Petr Šplíchal <psplicha@redhat.com>
     width = 79
     quarter = 1
+    week = 0
     separator = #
     separator_width = 20