Famous quote time! I forget who said it, and the number varies a bit from one retelling to the next, but one that has always stuck in my mind since I heard it is the following:

“I’d fire any programmer who spends more than [10 | 25]% of his time coding.”

I’ve always taken this as an admonition to spend time charting out solutions before building, instead of churning out stream of consciousness spaghetti code, personally.

Any thoughts from the broader community on the topic?

10 in binary is 0110
25 in binary is 1101
10 | 25 == 1111 == 27%

0.27 * 7 days == 1.89 days a week

1.89 * 24 hrs == 45.36

nah, I'd stick with 35-40 hrs a week

From experience, I'd say that quote is more applicable to a corporate coding context, where you need to read and understand lots of pre-existing unchangeable code before even figuring out where to put your changes.
It's likely that the development methodology will be more waterfall-based and have more bureaucracy to get past before beginning the actual writing of code in such a context.

I do a fair amount of prototyping and small projects using a more agile, hands-off methodology and when you're staring at a blank canvas, you will probably form a general idea of the painting and paint in broader, instinctive strokes at first, refining as you iterate.

Essentially, I feel the amount of time spent coding is inversely proportional to the maturity and intended degree of completeness of the project.