Take the 2-minute tour ×  The instructions will be up during
today.  The instructions will be up during the day.  Which one
is correct?  share|improve this question add comment  3 Answers
up vote 2 down vote accepted  To expand on Barrie's answer, they
both seem correct to me, but they do mean different things.  If
the instructions are up "during the day", then I might not
expect them to be up at other times, such as overnight. It
depends what "the day" means to your audience, but I wouldn't
expect something that is up "during the day" to be available at,
say, 9pm.  If the instructions are due to be be up "during
today", I would expect them to start being available at some
point today, and to remain available once they arrived.
share|improve this answer Yes, the point is, that, the
preposition ‘during’ can stand before the noun ‘today’. – 
Barrie England Sep 30 '11 at 13:41 add comment  Both are
grammatical, but they mean different things.  share|improve this
answer add comment  "During the day" is definite