Remove PY_TIMEZONE references (#547)

This changeset removes the PY_TIMEZONE configuration variable and updates all references to it to refer directly to pytz.utc instead.  It also cleans up a few of the import statements and removes those that are no longer needed (like the current_app reference from Flask).

Signed-off-by: Carlo Costino <carlo.costino@gsa.gov>

app/main/forms.py

@@ -4,7 +4,7 @@ from itertools import chain
 from numbers import Number
 
 import pytz
-from flask import Markup, current_app, render_template, request
+from flask import Markup, render_template, request
 from flask_login import current_user
 from flask_wtf import FlaskForm as Form
 from flask_wtf.file import FileAllowed
@@ -74,8 +74,8 @@ def get_time_value_and_label(future_time):
     return (
         future_time.astimezone(pytz.utc).replace(tzinfo=None).isoformat(),
         '{} at {} UTC'.format(
-            get_human_day(future_time.astimezone(current_app.config['PY_TIMEZONE'])),
-            get_human_time(future_time.astimezone(current_app.config['PY_TIMEZONE']))
+            get_human_day(future_time.astimezone(pytz.utc)),
+            get_human_time(future_time.astimezone(pytz.utc))
         )
     )
 
@@ -93,20 +93,20 @@ def get_human_time(time):
 def get_human_day(time, prefix_today_with='T'):
     #  Add 1 hour to get ‘midnight today’ instead of ‘midnight tomorrow’
     time = (time - timedelta(hours=1)).strftime('%A')
-    if time == datetime.now(current_app.config['PY_TIMEZONE']).strftime('%A'):
+    if time == datetime.now(pytz.utc).strftime('%A'):
         return '{}oday'.format(prefix_today_with)
-    if time == (datetime.now(current_app.config['PY_TIMEZONE']) + timedelta(days=1)).strftime('%A'):
+    if time == (datetime.now(pytz.utc) + timedelta(days=1)).strftime('%A'):
         return 'Tomorrow'
     return time
 
 
 def get_furthest_possible_scheduled_time():
     # We want local time to find date boundaries
-    return (datetime.now(current_app.config['PY_TIMEZONE']) + timedelta(days=4)).replace(hour=0)
+    return (datetime.now(pytz.utc) + timedelta(days=4)).replace(hour=0)
 
 
 def get_next_hours_until(until):
-    now = datetime.now(current_app.config['PY_TIMEZONE'])
+    now = datetime.now(pytz.utc)
     hours = int((until - now).total_seconds() / (60 * 60))
     return [
         (now + timedelta(hours=i)).replace(minute=0, second=0, microsecond=0)
@@ -115,7 +115,7 @@ def get_next_hours_until(until):
 
 
 def get_next_days_until(until):
-    now = datetime.now(current_app.config['PY_TIMEZONE'])
+    now = datetime.now(pytz.utc)
     days = int((until - now).total_seconds() / (60 * 60 * 24))
     return [
         get_human_day(

app/main/views/performance.py

@@ -3,7 +3,8 @@ from itertools import groupby
 from operator import itemgetter
 from statistics import mean
 
-from flask import current_app, render_template
+import pytz
+from flask import render_template
 
 from app import performance_dashboard_api_client, status_api_client
 from app.main import main
@@ -12,8 +13,8 @@ from app.main import main
 @main.route("/performance")
 def performance():
     stats = performance_dashboard_api_client.get_performance_dashboard_stats(
-        start_date=(datetime.now(current_app.config['PY_TIMEZONE']) - timedelta(days=7)).date(),
-        end_date=datetime.now(current_app.config['PY_TIMEZONE']).date(),
+        start_date=(datetime.now(pytz.utc) - timedelta(days=7)).date(),
+        end_date=datetime.now(pytz.utc).date(),
     )
     stats['organisations_using_notify'] = sorted(
         [