Postal workers in Hamilton are off the job.
Eighteen hundred Canada Post workers walked out after midnight in the Hammer.
The rotating strikes continue in communities across the country.
Meantime, the postal union has also imposed an overtime ban, meaning workers can refuse to work beyond their normal eight hour days.
This comes as Canada Post faces a days long backlog of parcel deliveries, with more than 150 trailers filled with parcels sitting at three key processing centres across the country.