the practice sessions will be

The test for the official license will occur the first week of April, and the
practice sessions will be from 2:00 pm until 05:00pm each of the four
Mondays in March.

session: 時段
practice sessions : 演練時段; 作業時段

官方執照的測試將於四月份第一週開始進行, 而演練時段訂在三月份每週一(計有四個週一)下午2:00至5:00.


2013-12-31 12:25:11 補充：
測試 ---> 考試

2013-12-31 13:57:25 補充：
官方執照的考試將於四月份第一週進行, 而演練時段訂在三月份每週一(計有四個週一)下午2:00至5:00.

因無前後文, 本句的license看不出是什麼證照.
test也不限於筆試, 例如駕照的鄙視與路考都算.
有些技工執照也包含筆試與術科鑑定.

2013-12-31 13:58:41 補充：
訂正: 鄙視 --> 筆試
中文輸入亂跳沒注意, 抱歉

session:期程
test 筆試
practice 實作

The test for the official license will occur the first week of April, and the practice sessions will be from 2:00 pm untill 05:00pm each of the four Mondays in March.

正式測驗會在四月的第一周舉行。三月的每個星期一下午兩點到五點則開放給大家練習。

session通常指某項活動舉行的那段時間
EX: Q& A session : 問答時間

"session" means "A period of time devoted to a specific activity". In your questioned sentence, "practice session" can be understood as "練習班(課)".