```ruby
#
# config/initializers/scheduler.rb

require 'rufus-scheduler'

# Let's use the rufus-scheduler singleton
#
s = Rufus::Scheduler.singleton

s.cron '30 1 * * *' do
  Rails.logger.info "Running working day validation at #{Time.now}"
  WorkingDayValidationController.validate_previous_working_day
end

s.cron '30 1 * * 5' do
  Rails.logger.info "Running working week validation at #{Time.now}"
  WorkingDayValidationController.validate_previous_week
end

s.cron '30 1 1 * *' do
  Rails.logger.info "Running working month validation at #{Time.now}"
  WorkingDayValidationController.validate_previous_month
end
```

Use environment variable SCHEDULE_VALIDATION_TASKS to enable/disable scheduling of validation tasks
user
```ruby
#
# config/initializers/scheduler.rb

require 'rufus-scheduler'

# Let's use the rufus-scheduler singleton
#
s = Rufus::Scheduler.singleton
if ENV['SCHEDULE_VALIDATION_TASKS']
  s.cron '30 1 * * *' do
    Rails.logger.info "Running working day validation at #{Time.now}"
    WorkingDayValidationController.validate_previous_working_day
  end

  s.cron '30 1 * * 5' do
    Rails.logger.info "Running working week validation at #{Time.now}"
    WorkingDayValidationController.validate_previous_week
  end

  s.cron '30 1 1 * *' do
    Rails.logger.info "Running working month validation at #{Time.now}"
    WorkingDayValidationController.validate_previous_month
  end
end
```
assistant