Complex sentence: Construction work commenced at the new site on 14 November, 1969, and in 1970, Johnstone Gallery openings were changed from the traditional Sundays to Friday evenings, due to the unexpectedly prompt completion of the theatre.
Split into simpler sentences: Construction work commenced at the new site on 14 November, 1969. In 1970, Johnstone Gallery openings were changed from the traditional Sundays to Friday evenings, due to the unexpectedly prompt completion of the theatre.