by the end of the day/today What is the difference (and meaning) between the following phrases: 1. by the end of the day 2. by the end of today 3. by the end of the day today Lots of times I hear the 3rd one... are they interchangeable? Can I say 2 instead of 3 and save the same meaning ?Let me add 4th one phrase: 4.by the end of the day Friday Can I skip "the day" part?