Delta Glass is closed on the following dates:
| Christmas holidays 2017-2018 | 23 dec 2017 t/m 1 jan 2018 |
| Easter Monday | 2 april 2018 |
| Kingsday | 27 April 2018 |
| Ascension Day | 10 and 11 May 2018 |
| Pentecost Monday (Whitmonday) | 21 May 2018 |
| Summer holidays | 21 July till 12 aug 2018 |
| Christmas holidays 2018-2019 | 22 Dec 2016 till 1 Jan 2019 |