Help with a SQL query function

Hello!

I would like your help to understand this function correctly, please: @eventDate > = Days Ago (6) AND @eventDate < Days Ago (5)

I want to filter only those who received an email 6 days ago, the first part of the condition wouldn't be enough? The @eventDate < Days Ago (5) would be a security way to guarantee that only users from six days ago will be filtered? Like, six days ago and no number lower than five days? 

Thank you in advance!

Thais