Returns the week start (e.g. :monday) for the current request, if this has been set (via Date.beginning_of_week=). If Date.beginning_of_week has not been set for the current request, returns the week start specified in config.beginning_of_week. If no config.beginning_of_week was specified, returns :monday.
# File activesupport/lib/active_support/core_ext/date/calculations.rb, line 17 def beginning_of_week Thread.current[:beginning_of_week] || beginning_of_week_default || :monday end