今天休息 既 英文

If you are asking the one who is talking to you to take that action, then you will say

You can take a day off, please leave a contact number.......

If you are telling the one who is talking to you about someone else, then you will say

He/she has a day off today, would you like to leave a contact number for him/her?

If you are the one that taking a day off(may be your store is close?), then

We are closed today, would you like to leave a phone number?

Commonly uses:
S/He or (name) is off today, may I take a message?

Or you can say:
S/He or (name) is taking a day off, may I take a message?
(Not that common)

I am afraid she/he is on annual leave today, may I take your contact details?

OR

I am afraid she/he is out of office today, may I help you at all?

"那個人的名" is day off, please leave you name and phone number.