In a new statement about the industrial action, planned by drivers as part of an ongoing pay dispute, Stagecoach said the strike will affect Barnsley, Rotherham, Dearne Valley and West Yorkshire services from January 1 and Sheffield services from January 2.
Most services will not run except for dedicated school buses so passengers are advised to make alternative travel arrangements.
Stagecoach also offered an apology to customers for the disruption that the strike action will cause.
The operator said that during the strike it will be running services on a reduced timetable, beginning from Tuesday, January 4.
The services are:
1 - High Green - Batemoor (Monday to Friday)
25 - Woodhouse - Bradway (Monday to Friday)
57 - Sheffield - Stocksbridge (Monday to Friday)
120 - Halfway - Fulwood (Monday to Friday)
22X - Rotherham - Barnsley (Monday to Friday)
Industrial action over pay ‘below inflation’
According to Unite, its members have been paid below inflation for more than a decade.
Earlier in December, Unite voted to reject Stagecoach's new salary offer.
Members walked out in the week running up to December 3 after reportedly being promised a two per cent salary increase in November, which Unite referred to as a 'poverty pay rise.'
The new deal promised a nine per cent raise in six months, consisting of a six per cent increase in hourly salary, followed by a three per cent increase in the following six months.
The offer 'fell far short of their expectations,' Unite said.
Which services are not affected by the industrial action?
Here is a list of services in Sheffield which will still run a normal service
All Supertram services
X17 - Barnsley - Meadowhall - Sheffield- Chesterfield - Matlock
43/44 - Sheffield - Woodseats - Chesterfield
50/50a - Sheffield - Mosborough - Eckington - Chesterfield
53 - Sheffield - Mosborough - Eckington - Mansfield
65 - Meadowhall - Sheffield - Buxton
80/80a Sheffield - Crystal Peaks - Killamarsh - Chesterfield
Services in Rotherham which will still run a normal service:
19/19A Rotherham - Worksop
Services in Barnsley which will run a normal service:
X17 - Barnsley - Meadowhall - Sheffield- Chesterfield - Matlock