Is there a way to enter command line mode for a single command directly from insert mode?

Question

I'd like to go directly into command line mode from insert mode, enter a single command (say :r !date which inserts the date) and then go immediately back into insert mode.

Basically something similar to the Ctrl-o command for entering normal mode for a single command then returning to insert mode.

Answer 1

I believe

<C-o>:r !date

will work