You are half-correct. "Was to be" is not a super common phrase, I would say it's much more common in literature than in everyday life. In general, "was to be" is a phrase that conveys an attitude that you have now gained an understanding about a past circumstance that you did not have at the time. But to answer your question, "was to be" has two similar but different meanings depending on the context. For example, Meaning 1: "Was to be" is a way of saying that a past circumstance has proven itself to possess a quality that can only be understood with the passing of time and reflection. "Leaving my ex-girlfriend was to be the first of many challenges ahead" means "Leaving my ex-girlfriend had proven itself to be the beginning of many challenges". The speaker, able to reflect on the past, can speak confidently that breaking up with their girlfriend was only the 1st challenge out of many challenges. However, at the time of the breakup, there was no way for the speaker to know that there were even more challenges yet to come. Therefore, "was to be" in this sentence implies that the speaker has gained an understanding that since the breakup, there were even more challenges that arose. Here's another example: "That Saturday was to be the worst day of my life" There is no way to know if the day you are experiencing today is going to be the worst of your life. But, after some time passes, you can gain an understanding that a particular day was truly the worst day of your life. Therefore this sentence implies that time has passed since that Saturday, and you now understand it was the worst day of your life. Meaning 2: Your assumption was correct. The second meaning is a way of saying something is supposed to be, or something was supposed to happen. "this homework was to be completed 3 hours ago, but you failed to accomplish that task because you were too busy playing video games"

Yes it does. EG: He was to be a lawyer but he failed the exams. He was to be in London yesterday but he missed the train. She was to be married, but the guy never turned up for the wedding. Example with the plural form = They were to be married but broke it off. These parts for the car - they were to be used for this car but do not fit. I hope this helps.

How Can I write the sentence if I have to say that it has to be held today…. Means at the end of the day can we say this sentence