Why can't my immediate boss assign me the task in time ?

Yes, you are panicking. Not knowing what the task is, I cannot say why your boss gave it to you so late and can only guess at what you should do. You should start out with a plan you intend to follow to accomplish the task (a plan you can pass to somebody else when your boss needs you to stop) and start following the plan. If you're not finished by Monday, I guess you can either ask for extra time or give the plan and the part you've finished to your boss to pass to someone else to finish.

From a management perspective giving out a task to be completed is complex. Give it out too early and the person marks it as low priority and does not start it for weeks, then of course fails to complete it on time. Give it out too late and your problem occurs. It is a fine balance. Trouble is many managers are professional managers and have no competence in the areas they are managing, so don't know the time needed for tasks to be completed. Also though managers know that many times people take longer than they should to complete a task - saying they need a month to complete the task, when all the worker really needs is 5 days. I am not saying that this is the case here but many people like to 'pad' the time need in order to ensure they have time to complete the task comfortably. Remember that sometimes demands come from other departments at the last minute and they have no idea of how long something takes to complete. You manager may be doing the best he can and he may not have known before the meeting he went to this morning and he is simply trying to do the best he can. This may seem as if I am sticking up for the manager, I am not, I am simply looking at the problem from the manager's perspective. I have managed teams for a large part of my life and have had similar "demands" thrust on me at the last minute. Despite my best protestations the task is still needed - but I normally explain this to the person asked to provide the answer.

HI! Your apprehensions are understandable. You have done your part and you have told your boss that this job cannot be completed within few days. He may realize it later. You take your own time to complete the job, because you can not compromise with quality of the job in hand, I suppose. All the best.

It is very hard when we have planned to get work done in a certain amount of time but then it is not assigned to us. You should speak to him about it, and explain that there is no way that you will be able to finish the work in the amount of time that he has told you to even though you are going to be working very hard on it. This is good because you would get longer to complete the work, and your boss would be able to take a little time to think about the ways in which he handles his staff, and how he could make it better in the future.

I can relate to this. But we cannot avoid that if something came up and we need to finish it in a flash. Maybe next time I should bargain or ask my boss to give me some more time or allowance to make those reports. And maybe I should be always prepared at all times when the need arises. Good luck.

Well, there's nothing else you can do but just do your job like your usual best. It is enough that you have told your immediate superior about the impossibility of the task to be finished at the date that he said it should be. It's like he's got fair warning already. So it's no longer in your hands if things didn't go the way he wants them to be because of his poor planning and judgement. Just as long as he sees that you're doing your usual best, he's got no right to complain.