Script changing dates to text

As variant you may replace dates with texts in place, it could be like

function main(workbook: ExcelScript.Workbook) {

// https://techcommunity.microsoft.com/discussions/excelgeneral/script-changing-dates-to-text/4468085

  fnDateToText(workbook.getActiveWorksheet().getRange("E:E").getUsedRange())
  fnDateToText(workbook.getActiveWorksheet().getRange("H:H").getUsedRange())

}

const fnDateToText = (columnRange: ExcelScript.Range) =>
  {
    const converted = columnRange.getValues().map(x => {
      const scalar = x[0]
      let dateAsText: number | string | boolean = null
      if (typeof scalar === "number") {
        const d = new Date(Math.round((scalar - 25569) * 86400 * 1000))
        dateAsText =
          d.getDate().toString().padStart(2, '0') + "/" +
          (d.getMonth() + 1).toString().padStart(2, '0') + "/" +
          d.getFullYear().toString()
      } else { dateAsText = scalar }
      return [dateAsText]
    })

  columnRange.setNumberFormatLocal("@")
  columnRange.setValues(converted)
  
  }

Function converts numbers (which dates actually are) in the column into text with date converted to "dd/mm/yyy". And ignores other values in such column.