opening night 
noun
The first night of a theatrical play or other entertainment.In most cases, we would probably still be there in the theatre on an interminable opening night....
- Days away from the opening night of the end of term musical, the leading lady is knocked unconscious.
- Avery has a strong art background but also went to a school of performing and visual arts, which helps him incorporate the visual aesthetics of performance and entertainment into opening nights.