rake -D time doesn't work!

Here's an example of me running rake -D time

526:project 526$ rake -D time
rake time:zones:all
    Displays all time zones, also available: time:zones:us, time:zones:local -- filter with OFFSET parameter, e.g., OFFSET=-6

52开发者_JAVA百科6:project 526$ 

It's running exactly how it should! Here's the output from about the -D flag that I get by running $ rake -h

-D, --describe [PATTERN]         Describe the tasks (matching optional PATTERN), then exit.

You just need to run rake time:zones:all or rake time:zones:us.