Abbreviations

[jack]

1. It is going to take 20 min.
2. It is going to take 20 mins. (For abbreviations, do I have to add -s?)

[Tdol]

You'll see both used.

[jack]

Thanks.

[Casiopea]

You're welcome, jack, and to save time and energy, you could always place "Thanks" at the end of your message, like this,

MESSAGE

What's the difference between cats and dogs?

Thank you in advance.
Thanks in advance.