They begin at home to Hampshire on Friday, 7 July and finish at home to Middlesex on Friday, 18 August.
All their home T20 matches will be played in Cardiff with six out of seven games played under floodlights.
The team will make a first-ever trip to Arundel to face Sussex in their first away fixture, on Sunday, 9 July.
The new schedule marks the first time that T20 games will not be interspersed with other formats.
The changes are designed to minimise players having to adapt back and forth between formats, and to maximise crowd appeal in better weather.
The quarter-finals of the competition will be played between 22 and 25 August with Finals Day at Edgbaston on Saturday, 2 September.
Glamorgan were quarter-finalists in the T20 competition in 2016, finishing second in the South group before losing to Yorkshire.
Glamorgan T20 fixtures in 2017:
7 July: Hampshire (h)
9 July: Sussex (a)
15 July: Somerset (h)
16 July: Essex (a)
21 July: Sussex (h)
23 July: Essex (h)
25 July: Gloucestershire (a)
28 July: Surrey (h)
30 July: Kent (a)
3 August: Gloucestershire (h)
4 Aug: Surrey (a)
10 Aug: Hampshire (a)
13 Aug: Somerset (a)
18 Aug: Middlesex (h)
Glamorgan will play all their T20 Blast matches in a 43-day block in summer 2017 after a revamp of the county cricket fixture schedule.