"They are coming here on December eighth."
Translation:Ellos vienen aquí el ocho de diciembre.
Because it doesn't literally translate as that in this instance, in other words it's not required.
This is the formula for writing dates:
el + day + de + month (+ de + year)
numeral for the day + de + name of the month + de + numeral for the year
To Spiceyokooko: Thanks for that. I also put "en". I am sure in other examples Duo has used "En" before a date but I may be wrong. You say it's not required, but is it wrong to put "En"?
I've written "van a venir aquí" instead of "vienen aquí" and it's wrong, why?
To Faby411280: Because you are saying "They are going to come here" and that is not what you were asked to translate. You were asked to translate, "They are coming here" Although both mean the same thing.