Need expression help for variable logic

[EMY9317]

I am modifying a working time off request flow.  In order to circumvent the lack of a date/time picker in MS Forms (there is only date, not time) I am attempting to Frankenstein some logical expressions with variables to combine them together into a date/time stamp that populates a new SP list item with the time the user entered into the form.  I can do this by concatenating the Start Time response fields to get a combined Start Time.  The problem is that when my flow creates a SP list item and that combined Start Time is used in the Date/Time column of the list, it sometimes shows the wrong time.  So I have to convert it into a timestamp that SP will accept.

The form has 3 drop downs (StartTimeHour for Hours [1-12], StartTimeMinutes for Minutes [quarter hours], StartTimeAM/PM for AM or PM).  

I am trying to:

1- Create a StartHour variable that checks to see if the StartTimeAM/PM response equals PM and if YES, add 12 hours to the StartTimeHour response value IF the value is less than '12', OR if equal to 12, return the StartTimeHour value unmodified, if StartTimeAM/PM does not equal PM, return StartTimeHour value unmodified.

Action - Initialize Var

Expression: if(equals('StartTimeAM/PM','PM'),if(less('StartTimeHour',12),add('StartTimeHour',12),'StartTimeHour,'StartTimeHour'.

2- Define a Start Date/Time variable that is in the correct format to populate into a date/time picker column in a SP list.

Action - Initialize Var to format StartDate into acceptable date format yyyy-MM-dd

Expression:

formatDateTime(variables('StartDate'),'yyyy-MM-dd')

Action - Initialize Var to combine the form response start date with the combined time fields.

Expression:

concat(variables('SPStartDate'),' ',variables('StartTime'))

Action - Initialize Var to convert the date time variable into UTC format for the SP list

Expression:

convertTimeZone(variables('StartDateTime'),'Central Standard Time','UTC')

I was able to complete the flow successfully with the correct time populated into the SP list when testing with an AM time (11am).  But the flow fails when I test with a PM time.  It is failing on  StartHour variable (#1 above) with the following error message: 
Unable to process template language expressions in action 'Initialize_variable_6' inputs at line '0' and column '0': 'The template language function 'lessOrEquals' expects two parameter of matching types. The function was invoked with values of type 'String' and 'Integer' that do not match.'

I'm at a loss and I'm spinning my brain into mush with the logic flow on this.  What am I missing?  Is there a way to do this better?  Do I just need to correct my expression?  Clearly I'm a beginner and I'm self-teaching as I go.

[v-liwei-msft]

Hi @EMY9317 

The problem is that StartTimeHour returns a string instead of a number.
You need to use the int function before the parameter StartTimeHour, for example:

if(equals('StartTimeAM/PM','PM'),if(less(int('StartTimeHour'),12),string(add(int('StartTimeHour'),12)),'StartTimeHour,'StartTimeHour')

Best Regards,

Levi

[EMY9317]

That does not appear to work.  I'm getting an error when I try to update the expression that the expression is invalid.

[Chriddle]

Have a look at following expression:

parseDateTime('01/31/2023 2:15 PM')

The output of this expression is 2023-01-31T14:15:00.0000000

So just concatenate such a string and it's good.

[EMY9317]

I'm not clear how this will identify the afternoon time selections and then add 12 hours to convert to military time before converting to UTC for the SP list?  Where should I use this expression in my flow?

[Chriddle · Accepted solution]

That's the point, you don't have to add 12 hours, just look at the expression and it's output.

You have to create a string like '01/31/2023 2:15 PM' from your input values.

And you already have mentioned the convertTimezone function:

convertTimeZone('01/31/2023 2:15 PM','Central Standard Time', 'UTC')

Output: 2023-01-31T20:15:00.0000000Z

[EMY9317]

Thank you.  I understand what you are saying now and I added the ParseDateTime before the convertTimeZone and tested with several requests spanning AM and PM and it seems to have done the trick!