I prefer: 'Delivery is scheduled for today.'
Yes, that sentence is grammatically correct.
It's the terrible weather
The sentence "Lets get into something formal today" is not correct grammar due to improper use of preposition.
Meet with Scott and I
Kelly didn’t have any lunch today.
Let's just hope that the bus is still on schedule. I will try to squeeze you into my schedule later today.
"We were informed it will be corrected today" is a correct sentence. However, it might sound a little better to say "We were informed that it will be corrected today."
I gave explicit instructions to my aide for your schedule, today.
Yes, "by the end of today" is a correct way to refer to something that will happen or be completed before the current day ends.
it means that the package is schedule to be delivered on the day that is market
No, it is not.
It is correct.
Yes, that sentence is grammatically correct.
It's the terrible weather
The sentence "Lets get into something formal today" is not correct grammar due to improper use of preposition.
If you capitalize the first letter of the sentence and place a period at the end, use an apostrophe for the contraction for 'it's', it is a correct sentence: It's going to be a great night today. Although correct as a sentence, it would make more sense if it said: It's going to be a great night tonight.
Both, you can reword it accordingly to how you plan to deliver the sentence.