Date compare is null

Hello 

Below is the fixed code

a!localVariables(
  local!weeknum: if(
    a!isNotNullOrEmpty(ri!startDate),
    weeknum(ri!startDate),
    {}
  ),
  local!day: if(
    a!isNotNullOrEmpty(ri!startDate),
    day(ri!startDate),
    {}
  ),
  local!month: if(
    a!isNotNullOrEmpty(ri!startDate),
    month(ri!startDate),
    {}
  ),
  local!year: if(
    a!isNotNullOrEmpty(ri!startDate),
    year(ri!startDate),
    {}
  ),
  local!dayofWeek: if(
    isnull(ri!startDate),
    "Please Select a Date ",
    weekday(ri!startDate) - 1
  ),
  local!startWeekDay: if(
    isnull(ri!startDate),
    0,
    if(
      local!dayofWeek <> 1,
      ri!startDate - local!dayofWeek + 1,
      {}
    )
  ),
  local!endWeekDay: local!startWeekDay + 4,
  local!monday: local!startWeekDay,
  local!tuesday: local!startWeekDay + 1,
  local!wednesday: local!startWeekDay + 2,
  local!thursday: local!startWeekDay + 3,
  local!friday: local!startWeekDay + 4,
  a!formLayout(
    label: "Form",
    contents: {
      a!sectionLayout(
        contents: {
          a!dateField(
            label: "Start Date",
            labelPosition: "ABOVE",
            value: today(),
            saveInto: ri!startDate,
            validations: {}
          )
        }
      ),
      a!integerField(
        label: local!monday,
        labelPosition: "JUSTIFIED",
        saveInto: {},
        refreshAfter: "UNFOCUS",
        validations: {}
      ),
      a!integerField(
        label: local!tuesday,
        labelPosition: "JUSTIFIED",
        saveInto: {},
        refreshAfter: "UNFOCUS",
        validations: {}
      )
    },
    buttons: a!buttonLayout(
      primaryButtons: {
        a!buttonWidget(
          label: "Submit",
          submit: true,
          style: "PRIMARY"
        )
      },
      secondaryButtons: {
        a!buttonWidget(
          label: "Cancel",
          value: true,
          saveInto: ri!cancel,
          submit: true,
          style: "NORMAL",
          validate: false
        )
      }
    )
  )
)

Changes I have done

1.  local!dayofWeek - cannot comapre ri!startDate with null() as the type of ri!startDate is Date, hence we need to use isNull() function to check if it is null.

2. local!startWeekDay - if ri!startDate is null we local!dayofWeek holds a text value hence no mathematical operations can be done on it, so I have added a null check and set the value to zero if ri!startDate is null.

Hope this helps.