timecalc | scratch pad for time and date parsing

Hi I have a parent child relationship between two entities- PositionSummary and PositionDetail.

Here are the models.

I current have parent page that properly navigates to a different child page. The Child page has the stand grid of child records- AND it also has 'Create' link to add a new child record.

Under standard Entity Framework Scaffolding the 'Create' page has standard html'dropdown' lists for the fields that are linked to 'lookup' values.

Below are some screen shots:

The Position Details link navigates to the child records:

The Create New Link brings up the standard scaffolded create page:

The PositionId field shows the full list of choices for parent lookup -rather than bringing in parent key default.

Here is code for create page:

For the create page my question is- how can I default that value of PositionID/PositionNbr to be what it would be for all the existing child records on the previous grid page? This should be a standard child record create scenario- where parent key is prepopulated

I am not finding a whole lot of good examples on a google search for how to prepopulate the parent foreign key in the child records -particularly when the creation is on a separate create page.

Hope my question is making sense- thanks in advance ...

Modified- here is code as code

I'm using a date/time picker that I found on https://material-ui-pickers.dev/ and wanted to use it with the moment.js library. I'm having some issues. I have a form that collects a start time and an end time. I wanted to use the moment.js "diff" method to calculate the difference in hours. I keep getting "20.4234254" or similar, regardless of what dates & times I enter.

The format of the date as it's being held in state and managed by moment.js is: "Wed Jul 08 2020 21:51:23 GMT-0700 (Pacific Daylight Time)".

I am trying to build a simple multiplication game using pure Javascript. When I click start button it calls a function timeCalc(). The timeCalc function declares a variable name fullTime with the value of 7 and sets interval and after every second fullTime is decreasing by 1. when it decreases to 1 it sets the fullTime value to 7.

If I click on the start button many times the fullTime decreses so fast and in a disorder way even If I have done clearInterval() at the begining. I want to decrese the fullTime from 7 in a normal way even if I click it many times. what happens behind the scene?

Here is my code snippet. Thank you.

I am just trying to get code to work where the code asks again for an answer, if text or a symbol is entered, instead of a required integer:

I have a dataframe df with a column date of birth. The head looks like:

I'm calculating the difference between the date in the database and at the current time. I use this a function called TimeAgo() in my PHP code.

TimeAgo() code:

I'm a completely beginner and I write code in my free time. Can anyone explain me please why sometimes my Pomodore Clock is stuck when it hits 0 0 1. (hours, minutes, seconds)

I can start it in one tab in chrome and it will work for unpredictable amount of cycles and then for no reason it will stop at 0 0 1, just before starting next cycle. I want it to work continuous (work, break, work, break, etc.) until I hit reset button...

Is there better way to handle time in JS?

Code: