Complex sentence: While never proclaimed officially, participation and official support for Sedantag celebrations varied over time, and working class leaders never really accepted it, Sedantag became a de facto national holiday, last celebrated in 1918.
Split into simpler sentences: While never proclaimed officially, participation and official support for Sedantag celebrations varied over time, and working class leaders never really accepted it. It became a de facto national holiday, last celebrated in 1918.