To use or not to use 'on' before the names of the days of the week
Usually, days of the week are written with the preposition 'on'. But sometimes, in news reports, I see that 'on' is omitted. For example, 'Most of the goods were sold Wednesday'. When is it possible not to use the preposition ? Or is it safer :) to write or say 'on' before the names of the days?
Now a days there is a growing tendency to use time nouns as adverbial objectives without preposition. Both usages are fine, but without preposition is finer because languages like rivers change courses for ease and need.
It has nothing to do with "laziness."
The "on-less form is quite common, if not more common, in casual speech and is used in other contexts and registers, as well.
Most day-of-the-week and similar time phrases have no preposition:
- Last Monday
- Next Monday
- Yesterday, etc.
It is a natural progression to also simplify phrases like "on Monday" to "Monday" in a parallel manner.
In fact, the word "tomorrow" used to be "on the morrow" and has changed to the single-word form we know today. That was not due to laziness, but simply the normal change languages undergo.
I also think people omit it in compound sentences (probably because they get lazy). I hear this in conversation, but also in casual online writing.
"Went we out Saturday night, and then had brunch on Sunday morning."
I don't know why, but it feels OK to omit the first 'on' but people usually include the second one.