The phrase "busy time" refers to a period in which a person or a place is filled with a lot of activity or work. It means there is a lot to do and not much free time. Full definition
Delivery and lead times — at busy times of year you need to be realistic about lead times for any custom orders and also ensure that the item arrives on time! (blog.folksy.com)
As you might already know, summertime is a very busy time for real estate agents. (blog.myhtr.com)
This can be especially helpful during busy times of the day, and before bed. (myorganicformula.com)