https://wakatime.com/blog/37-when-is-time-tracking-too-accur...
The default 15 mins is very accurate, and only represents time typing not time working.
How much time it took you to build first version and whole product? Any advice for starters?
May 3 2013 - Started development Flask website & Vim plugin (https://wakatime.com/blog/1-why-i-built-wakatime)
June 25 2013 - Finished Vim plugin and Website (https://github.com/wakatime/vim-wakatime/commit/4346a055e301...)
July 1 2013 - Started Sublime plugin (https://github.com/wakatime/sublime-wakatime/commit/b7fe36f8...)
July 15 2013 - Finished Sublime plugin and public launch (https://news.ycombinator.com/item?id=6046227)
Unfortunately I don't have WakaTime data until after finishing the Vim plugin, but everything after that I can see how long the actual coding took by dogfooding.
1: https://wakatime.com/about
2: https://news.ycombinator.com/item?id=6046227
For anyone thinking it's egregiously difficult to start a solo-project: You're right, but if you stick with it your persistence will pay off. For solo-products, I think grit is the deciding factor between success and failure.