comma before 'when' [in motto; conjunction]: what you..., when you

[promy]

Hello, everyone!

I need some assistance with writing a company motto with proper punctuation. It's quite a common phrase, but I would appreciate to hear people who consider themselves to be experts in punctuation.

There it goes:
Doing what you said you were going to do(,) when you said you were going to do it.

If this phrase had a third part like, for example, "and how you said you were going to do," this would be a serial construction and I would have less doubts about the comma in the parentheses. Nevertheless, can a comma be justified in this very case?

Thank you in advance!

 

[Copyright]

A comma or dash -- definitely.

 

[promy]

Thank you for your opinion, I will surely take it into consideration. However, I would appreciate some more detailed explanation, if possible.

 

[Copyright]

It's relatively simple. First, it's too long for a motto, so you need to break it in half. Second, you need the pause in there for dramatic effect.

You also need to put it all in the present tense.

 

[natkretep]

I can see what your problem is, promy. We'd normally say 'We need to be doing this thing (object) at this time (time adverbial​)' without internal punctuation, only 'this thing' is replaced by 'what you said you were going to do' and 'this time' with 'when you said you were going to do it'. I would say that the sentence would work much better in speech, and to help the reader make sense of it more quickly we might try to help them through the punctuation (as Copyright has suggested). But I'm still a bit uncomfortable with a comma between the object and the time adverbial. I'm also tempted to use italics:

Doing what you said you were going to do when you said you were going to do it.

as that reflects the stress pattern in speech.