FormatDateTime Argument

Help, please, about clock methods. 

Taifun already tried to give me a bit of information about, on another post where I asked whether it is possible to point the exact block affected by Runtime Error. 

Either at the first launch, when the TinyDB store is empty of the date of a last computation, or at the initialization of the App's Screen1 when I have previously stored & got a date, I am warned of the following Runtime Error.

Not good complete Gregorian Calendar format, not good [MM/dd/yy hh:mm a] format.

So, the big question is: what is the argument for the family to which owes the FormatDateTime method?

--

Please post screenshot of your relevant blocks and explain what result you are expecting.

You may also want to take a look at extension below which has features that you see in the attachment.

https://sourceforge.net/projects/appybuilder/

--

As required by Taifun and Hossein, please take ref. to the following screenshots (it is an app to report the accumulated working time in different slots of time):

--

you can't store an instant in TinyDB, convert it into milliseconds using the GetMillis method and later after reading from TinyDB convert it back into an instant

--

Thanks, that's an answer?

--

I made mistake, It had to bè a ! not a ?. Problems when I write on cell without glasses 

--

I am so sorry to bother yet, but:

Same runtime also with [0] at the "ValueTagNotThere" slot

Second Runtime Error:

What's wrong?

--

Second point (apparently) solved by feeding Duration with "instants":

--

...and saturday night I found the mistake: I used the right arguments for the wrong method (correcrt MakeInstantFromMillis, instead of GetMillis).

In fact, it works.

--