A: Did you go to Sally’s birthday party?
B: Sure I did. We had a whale of a time at the party Saturday night. It’s a pity you were out of town.
A: I wish I were at the party with you guys. By the way, do you have any plans for the National Day holiday?
B: I will go on a tour around Spain.
A: Enjoy your vacation! I hope you have a whale of a time.
Note: This is American slang from around 1910. It simply means to “have fun.” The blue whale being the biggest creature on earth, a “whale of” anything is “a large amount of” it. Having a whale of a time is having a lot of fun time.