Finally, the Evaluation stage took place and did not take the full ten days that was projected.
Above is a sentence from a report I am preparing. I had originally written "were" but changed it to "was" after deciding that
[full ten days] was a compound subject. It still doesn't feel right though, and I wonder if indeed both "was" and "were" are correct in this situation?
Could anyone please elaborate on this? Reference to sentence/phrase structure would also be appreciated.