Do I have to keep the Mastery of Timeways buff up constantly for the next 5 weeks to get the mount? /u/Sardinesqq World of Warcraft

I don’t want to have to constantly refresh a 3h buff after doing my dungeons for the week. Can I let it drop and just get it again each week?

I don’t want to have to constantly refresh a 3h buff after doing my dungeons for the week. Can I let it drop and just get it again each week?