Can I partition my HDD external backup to create 2 passports from 2 macbooks

[Slimmyhendrix]

I bought a WD 1tb HDD backup.
I have 2 MacBook airs.
I want to backup both.
Can I do this on one HDD or do I need 2?

 

[FreemanW]

Yes, you may partition one physical drive with two partitions, discrete unique names for each and point Time Machine at the chosen partition from each MacBook Air.