timePeriodType property

Gets or sets one of the constants of
 // Create a new Excel Document.
 final Workbook workbook = Workbook();
 // Accessing sheet via index.
 final Worksheet sheet = workbook.worksheets[0];

 sheet.getRangeByIndex(1, 1).setText('Conditional Formts');
 final now = DateTime.now();
 sheet
    .getRangeByIndex(2, 1)
    .setDateTime(DateTime(now.year, now.month, now.day - 1));
 sheet
    .getRangeByIndex(3, 1)
    .setDateTime(DateTime(now.year, now.month, now.day));
 sheet
    .getRangeByIndex(4, 1)
    .setDateTime(DateTime(now.year, now.month, now.day + 1));
 sheet
    .getRangeByIndex(5, 1)
    .setDateTime(DateTime(now.year, now.month, now.day - 1));
 sheet
    .getRangeByIndex(6, 1)
    .setDateTime(DateTime(now.year, now.month, now.day + 1));
 sheet
    .getRangeByIndex(7, 1)
    .setDateTime(DateTime(now.year, now.month, now.day - 1));
 sheet
    .getRangeByIndex(8, 1)
    .setDateTime(DateTime(now.year, now.month, now.day - 1));
 sheet
    .getRangeByIndex(9, 1)
    .setDateTime(DateTime(now.year, now.month, now.day));
 sheet
    .getRangeByIndex(10, 1)
    .setDateTime(DateTime(now.year, now.month, now.day + 1));

 // Applying conditional formatting to "A1:A11".
 final ConditionalFormats conditions =
    sheet.getRangeByName('A1:A10').conditionalFormats;
 final ConditionalFormat condition1 = conditions.addCondition();

 //Set formatType.
 condition1.formatType = ExcelCFType.timePeriod;

 //Set CF Time period.
 condition1.timePeriodType = CFTimePeriods.tomorrow;

 //Set Color
 condition1.backColor = '#FF00FF';

 //save and dispose.
 final List<int> bytes = workbook.saveAsStream();
 File('ConditionalFormats.xlsx').writeAsBytes(bytes);
 workbook.dispose();
Implementation

ConditionalFormat class
