boss: Hey! this is your task A. It needs to be done by today.
me: Ok boss
....after sometime when I am halfway through the task....
boss: Hey! here is a task B which needs highest priority.
me: but i am already doing A and I am halfway
boss: No, B is on priority
me: ok
...at the end of the day...
boss: So I hope you have completed task A as I mentioned that was to be done by EOD.
me: ****instant rage****

.

I'm beginning to get angry enough at this that I may flip out next time it happens.

slap his teeth out, hand him resignation letter, time for a switch.

Your boss needs to read some scrum/agile books.

This is common with bad managers, sometimes it helps to mention that task B has a higher value for customers.

@justDeployIt @Floydian

What also helps when boss arrives with task A, is saying "End of day is going to be difficult, it needs <complicated made up words>, but if I do some overwork at home this evening and tomorrow evening I can have it ready by the the day after tomorrow".

When B arrives unexpectedly, you can work on both in a relaxed way. If B doesn't arrive, you have oceans of free time, and you still get to boast about your impeccable work ethic.

@Floydian

It's the only way to deal with non technical management.

Ideally, that manager/boss shouldn't exist at all, and you measure productivity through scrum points and guide teams using product owners which know how to plan priorities and refine features into executable tasks.

But if you have to deal with broken management structures (or worse, directly with clients), you sometimes have to present... alternative facts 😋

Tell him very politely that he needs (1) basic time management training, (2) basic man management training

True

@bittersweet your suggestion is just amazing!!!

We should include it in the developer playbook :)

The proper response is "put it on the sprint board and assign it to me."

"I don't have time for that"

"Then go to my team leader. I can do nothing more for you here."