“I love deadlines. I love the whooshing noise they make as they go by.” Douglas Adams
I have seen so many misunderstandings caused by this one…
Both until and by indicate ‘not later than’.
Until tells us how long a situation continues. If something happens until a particular time, it stops at that time.
I am staying in London until Friday. = I am currently in London and this situation will continue up to Friday.
The Works Council has given us until March 1st to sort out this problem. = We have from now up to March 1st to do this.
I need the projector until Thursday. = I already have the projector and need to keep it up to Thursday.
Until can also be used in negative sentences:
Updates will not be available until June. = June is the earliest you can expect to receive an update.
till vs. until – till is a less formal way of saying until.
by indicates a deadline or the end of a particular time period. It indicates that something will be, or needs to be, accomplished at, or before, a particular time, but no later.
I would appreciate it if you could send your updates by Thursday. = On or before Thursday, but no later.
I’ve got to finish this report by Monday. = Monday is the final deadline.
He should have sent it by now. = It should already be here.
You have to finish by 5pm. = 5pm is the latest time you can finish; you may finish before this time.
by vs. until – Note the different meanings in the following examples:
I need it by Monday. = Someone else has it and I want to get it from them.
I need it until Monday. = I already have it and want to keep it up to Monday.
I need to be at the office by 4pm. = I am at home, but have to go to the office before, or at, 4pm.
I need to be at the office until4pm. = I am at the office and cannot leave before 4pm.
accomplished – ausgeführt currently – derzeit Works Council – Betriebsrat projector – Beamer accomplished – realizzato currently – attualmente Works Council – consiglio aziendale, consiglio di fabbrica projector – proiettore