Spanish language Q&A Forum

What is the difference?

The kwiziq page "Ser vs Estar in Spanish: Using ser in Spanish (not estar) to talk about time, days, dates and seasons" (Ser vs Estar in Spanish: Using ser in Spanish (not estar) to talk about time, days, dates and seasons) says

   Hoy es lunes.  =  Today is Monday.  ("Today" is singular.)

but

   Son las tres de la tarde.  =  It's three o'clock in the afternoon.  ("It" is plural.)

Why are these different?

I do not have a Spanish keyboard so cannot put in the accents

This might be way off base, but while "I" (or "yo") is the most common personal pronoun in most all languages, when one combines "it", "he", "she" and "este" etc followed by nouns, the third person singular is the most commonly used conjugation. In Kwiziq quizzes and exercises, it seems that "yo" and "tu" are the ones that show up most often. The exercises would be better if they had a proportional focus on the pronouns/conjugations in line with how frequently they are used in real life.  

Hi.  Please tell me about the use of "al dar" for a time.  Thanks.