Many thanks for your suggestion!
In last release (V8057) you can now define something like:
Project starts the 20th of september 2017
[Prototype design] as [TASK1] lasts 13 days
[TASK1] is colored in Lavender/LightBlue
[Prototype completed] happens at [TASK1]'s end
We have added support to ISO 8601 standard.
You can also shorten month name to the 3 first characters.
So you can now have:
Project starts the 2017/9/20
Project starts on the 2017-9-20
Project starts the 20th of sep 2017
We do not support "september the 20th, 2017" yet but this will be added.
Many things remain to be done (for example, possibility to close some days like Saturday, Sunday or specific holidays...) This will be added shortly. Stay tuned :-)
About syntax, it's not that easy to find a simple one. Several tries are usually needed to find better ideas.
So do not hesitate to play with our proposal and to make suggestions: nothing is fixed right now, so you can help here!