Issues CSV time formats use to_s

app/views/projects/issues/index.csv.ruby

@@ -13,9 +13,9 @@ columns = {
   'Author' => 'author_name',
   'Assignee' => 'assignee_name',
   'Confidential' => 'confidential',
-  'Due Date' => -> (issue) { issue.due_date&.strftime('%Y-%m-%d') },
-  'Created At (UTC)' => -> (issue) { issue.created_at&.strftime('%Y-%m-%d %H:%M:%S') },
-  'Updated At (UTC)' => -> (issue) { issue.updated_at&.strftime('%Y-%m-%d %H:%M:%S') },
+  'Due Date' => -> (issue) { issue.due_date&.to_s(:csv) },
+  'Created At (UTC)' => -> (issue) { issue.created_at&.to_s(:csv) },
+  'Updated At (UTC)' => -> (issue) { issue.updated_at&.to_s(:csv) },
   'Milestone' => -> (issue) { issue.milestone&.title },
   'Labels' => -> (issue) { labels[issue.id].sort.join(',').presence }
 }

config/initializers/date_time_formats.rb

@@ -2,8 +2,10 @@
 # :medium - Nov 10, 2007
 # :long   - November 10, 2007
 Date::DATE_FORMATS[:medium] = '%b %-d, %Y'
+Date::DATE_FORMATS[:csv] = '%Y-%m-%d'
 
 # :short  - 18 Jan 06:10
 # :medium - Jan 18, 2007 6:10am
 # :long   - January 18, 2007 06:10
 Time::DATE_FORMATS[:medium] = '%b %-d, %Y %-I:%M%P'
+Time::DATE_FORMATS[:csv] = '%Y-%m-%d %H:%M:%S'