Previous versions, without quotes:
ALTER TABLE dbo.[voyage_completeness_check_period] ADD CONSTRAINT [c_voyage_completeness_check_period_reservation_month] CHECK ([reservation_month]>=1 AND reservation_month]<=12)
New version, with quotes while the datatype is integer:
ALTER TABLE dbo.ovoyage_completeness_check_period] ADD CONSTRAINT Tc_voyage_completeness_check_period_reservation_month] CHECK ( reservation_month]>='1' AND Dreservation_month]<='12')