I am writing a trigger where I am bringing in a Date/Field field from case. It has a letter in it 2023-02-10T16:15:35.000+0000 and when I try to subtract it with "DateTime.now()" I get an error "Date/time expressions must use Integer or Double or Decimal ".

This is my code 
trigger CaseTrigger on Case (before update) {
     for(Case cases: Trigger.new){ 
         if(cases.stopped_time__c != null){
             cases.Total_amount_of_time_in_Hours__c= (DateTime.now()-cases.stopped_time__c );
         } 
    }
}

When checking this challenge, I get an error stating that the quickContact Lightning Component could not be found. Including screenshots of the steps I took thus far. Any advice would be appreciated!

1. The Lightning component must be named quickContact (this comes as part of the package, confirmed in picture below)


2. Create a new action with Label Quick Contact and Name Quick_Contact on the Account object that invokes the quickContact component. (confirmed in picture below)

3. Add the appropriate interfaces to the quickContact component. (Hint: there are two.) (used the implements force:lightningquickaction AND the force:hasrecordid on line 1, confirmed in picture below)


4. Add the action to the Account Layout page layout. (added in picture below)

The following formula will calculate the number of working days (inclusive) between 2 dates. A working day is defined as Monday to Friday. Even if the start or end dates are a weekend, these are accommodated.

IF(AND((5 - (CASE(MOD( Start_Date__c - DATE(1900, 1, 6), 7), 0, 0, 1, 5, 2, 5, 3, 4, 4, 3, 5, 2, 6, 1, 0)) < (CASE(MOD(  End_Date__c  - DATE(1900, 1, 6), 7), 0, 0, 1, 0, 2, 1, 3, 2, 4, 3, 5, 4, 6, 5, 0)) ),
((( End_Date__c  -   Start_Date__c ) + 1) < 7)),
((CASE(MOD(  End_Date__c  - DATE(1900, 1, 6), 7), 0, 0, 1, 0, 2, 1, 3, 2, 4, 3, 5, 4, 6, 5, 0)) - (5 - (CASE(MOD(  Start_Date__c  - DATE(1900, 1, 6), 7), 0, 0, 1, 5, 2, 5, 3, 4, 4, 3, 5, 2, 6, 1, 0)))),
(((FLOOR((( End_Date__c  -  Start_Date__c ) - (CASE(MOD(  Start_Date__c  - DATE(1900, 1, 6), 7), 0, 0, 1, 6, 2, 5, 3, 4, 4, 3, 5, 2, 6, 1, 0))) / 7)) * 5) +
(CASE(MOD(  Start_Date__c  - DATE(1900, 1, 6), 7), 0, 0, 1, 5, 2, 5, 3, 4, 4, 3, 5, 2, 6, 1, 0)) +
(CASE(MOD(  End_Date__c  - DATE(1900, 1, 6), 7), 0, 0, 1, 0, 2, 1, 3, 2, 4, 3, 5, 4, 6, 5, 0))))

The Start Date and End Date fields are custom in the above example and can be replaced as required. If use of a DateTime field is required then the DATEVALUE function will be required.

I also recommend a simple field validation rule is added to check that the End Date is after the Start Date.