change of duty

[jkl]

Please correct my writing.Thanks

Thanks for informing me about the change of duty to pick up the Key.

Not sure if you are aware of my duty that I used to do Monday to Tuesday at 7.00am. Since my schedule has changed and "X" is availabe at this time you may also want to give this duty to "X".

[Speedwell]

Hmm, try this.

Thank you for informing me that the person whose duty it is to pick up the Key has been changed. (If you are the new person, try: Thank you for telling me that it is now my duty to pick up the key.)

I don't know if you are aware that I used to perform the head-count on Monday and Tuesday at 7:00 a.m. Because my schedule has changed, I am no longer available to do this. You may want to give X this responsibility since they are available at those times.

It is OK to use "they" to refer to one person if you do not know whether they are male or female. However, if you know X, you should use "he" or "she":

"You may want to give Jane this responsibility since she is available at those times." OR
"You may want to give John this responsibility since he is available at those times." OR
"You may want to give your assistant the responsibility since they are available at those times." (In this case you don't know the assistant, but you do know their schedule.)

[jkl]

Thank you very much for the correction.

[Speedwell]

OK, that helps. Consider, "Thank you for letting me know that X is now responsible for picking up the key."

[susiedqq]

How about:

Thank you for informing me about the change of duty concerning the key.

Change of Duty may be a regulation term. I wonder if this is military or office procedure talk.