Add option to specify start of the week

docs/user-guide/configuration.md

@@ -149,6 +149,13 @@ Globally configure how `dates` should be formatted. All [python's `strftime` dir
 
 Globally configure how `time` should be formatted. All [python's `strftime` directives](http://strftime.org) are supported.
 
+#### `options.week_start`
+
+Globally configure which day corresponds to the start of a week. Allowable
+values are `monday` (default), `tuesday`, `wednesday`, `thursday`, `friday`,
+ `saturday`, and `sunday`.
+
+
 ### Default tags
 
 Tags can be automatically added for selected projects. This is convenient when
@@ -211,6 +218,7 @@ stop_on_start = true
 stop_on_restart = false
 date_format = %Y.%m.%d
 time_format = %H:%M:%S%z
+week_start = monday
 log_current = false
 pager = true
 report_current = false

tests/test_utils.py

@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 """Unit tests for the 'utils' module."""
 
+import arrow
 import functools
 import os
 import datetime
@@ -13,8 +14,8 @@
 import pytest
 from dateutil.tz import tzutc
 
-from watson.utils import (get_start_time_for_period, make_json_writer,
-                          safe_save, parse_tags, PY2)
+from watson.utils import (apply_weekday_offset, get_start_time_for_period,
+                          make_json_writer, safe_save, parse_tags, PY2)
 from . import mock_datetime
 
 
@@ -41,6 +42,23 @@ def test_get_start_time_for_period(now, mode, start_time):
         assert get_start_time_for_period(mode).datetime == start_time
 
 
+@pytest.mark.parametrize("monday_start, week_start, new_start", [
+    ("2018 12 3", "monday", "2018 12 3"),
+    ("2018 12 3", "tuesday", "2018 12 4"),
+    ("2018 12 3", "wednesday", "2018 12 5"),
+    ("2018 12 3", "thursday", "2018 12 6"),
+    ("2018 12 3", "friday", "2018 11 30"),
+    ("2018 12 3", "saturday", "2018 12 1"),
+    ("2018 12 3", "sunday", "2018 12 2"),
+    ("2018 12 3", "typo", "2018 12 3"),
+])
+def test_apply_weekday_offset(monday_start, week_start, new_start):
+    with mock_datetime(_dt(2018, 12, 6), datetime):
+        original_start = arrow.get(monday_start, "YYYY MM D")
+        result = arrow.get(new_start, "YYYY MM D")
+        assert apply_weekday_offset(original_start, week_start) == result
+
+
 def test_make_json_writer():
     fp = StringIO()
     writer = make_json_writer(lambda: {'foo': 42})

watson/cli.py

@@ -14,9 +14,9 @@
 
 from . import watson as _watson
 from .frames import Frame
-from .utils import (format_timedelta, get_frame_from_argument,
-                    get_start_time_for_period, options, safe_save,
-                    sorted_groupby, style, parse_tags)
+from .utils import (apply_weekday_offset, format_timedelta,
+                    get_frame_from_argument, get_start_time_for_period,
+                    options, safe_save, sorted_groupby, style, parse_tags)
 
 
 class MutuallyExclusiveOption(click.Option):
@@ -57,6 +57,13 @@ def convert(self, value, param, ctx):
             # expected by the user, so that midnight is midnight in the local
             # timezone, not in UTC. Cf issue #16.
             date.tzinfo = tz.tzlocal()
+
+            # Add an offset to match the week beginning specified in the
+            # configuration
+            if param.name == "week":
+                week_start = ctx.obj.config.get("options", "week_start")
+                date = apply_weekday_offset(
+                    start_time=date, week_start=week_start)
             return date
 
 

watson/utils.py

@@ -161,6 +161,23 @@ def get_start_time_for_period(period):
     return start_time
 
 
+def apply_weekday_offset(start_time, week_start):
+    """
+    Apply the offset required to move the start date `start_time` of a week
+    starting on Monday to that of a week starting on `week_start`.
+    """
+    weekdays = dict(zip(
+        ["monday", "tuesday", "wednesday", "thursday", "friday", "saturday",
+         "sunday"], range(0, 7)))
+
+    new_start = week_start.lower()
+    if new_start not in weekdays:
+        return start_time
+    now = datetime.datetime.now()
+    offset = weekdays[new_start] - 7 * (weekdays[new_start] > now.weekday())
+    return start_time.replace(days=offset)
+
+
 def make_json_writer(func, *args, **kwargs):
     """
     Return a function that receives a file-like object and writes the return