Here's the 2012 Road Race Calendar of events updated. I'd advise that you check with the organisers before making your travel plans the event schedule can often change. However, as I write, these are the confirmed dates published by the organisers.
2012 Race Calendar
April
15th April Scarborough Spring National
27th & 28th April Cookstown 100
May
4th & 5th May Tandragee 100
Horice (Czech Republic)
15th, 17th & 19th May North West 200 - Northern Ireland
25th, 26th & 28th May Blackford’s Pre TT Classic - Billown Circuit, Castletown IOM
26th May – 1st June TT Practice - Mountain Circuit IOM
June
2nd June – 8th June TT Races - Mountain Circuit IOM
Full TT schedule here http://www.roadracingsupporters.com/forum/viewtopic.php?f=11&t=954
9th June Manx Telecomm Post TT - Billown Circuit, Castletown IOM
15th & 16th June Mid Antrim
22nd & 23rd Bush
24th June Scarborough Barry Sheene Road Race Festival
July
30th June & 1st July Kells
6th & 7th July Skerries 100
14th & 15th July Walderstown
9th - 12th July Steam Packet Southern 100 - 9th – 12th July
21st & 22nd July Scarborough Cock O The North Continental
28th & 29th July Aberdare Park
27th & 28th July Armoy
August
4th & 5th August Athea
8th, 9th & 11th Ulster Grand Prix and Dundrod 150
25th & 16th August East Cork
18th August – 31th August Manx Grand Prix –
September
8th & 9th September Killalane
15th & 16th September Scarborough International Gold Cup
2012 Race Calendar
April
15th April Scarborough Spring National
27th & 28th April Cookstown 100
May
4th & 5th May Tandragee 100
Horice (Czech Republic)
15th, 17th & 19th May North West 200 - Northern Ireland
25th, 26th & 28th May Blackford’s Pre TT Classic - Billown Circuit, Castletown IOM
26th May – 1st June TT Practice - Mountain Circuit IOM
June
2nd June – 8th June TT Races - Mountain Circuit IOM
Full TT schedule here http://www.roadracingsupporters.com/forum/viewtopic.php?f=11&t=954
9th June Manx Telecomm Post TT - Billown Circuit, Castletown IOM
15th & 16th June Mid Antrim
22nd & 23rd Bush
24th June Scarborough Barry Sheene Road Race Festival
July
30th June & 1st July Kells
6th & 7th July Skerries 100
14th & 15th July Walderstown
9th - 12th July Steam Packet Southern 100 - 9th – 12th July
21st & 22nd July Scarborough Cock O The North Continental
28th & 29th July Aberdare Park
27th & 28th July Armoy
August
4th & 5th August Athea
8th, 9th & 11th Ulster Grand Prix and Dundrod 150
25th & 16th August East Cork
18th August – 31th August Manx Grand Prix –
September
8th & 9th September Killalane
15th & 16th September Scarborough International Gold Cup