# Custom columns: Formulas and custom dates/times

**URL:** <https://discuss.workflowgen.com/t/custom-columns-formulas-and-custom-dates-times/842>\
**Category:** Workflow Portal\
**Created:** [August 14, 2017, 6:35pm UTC](https://discuss.workflowgen.com/t/custom-columns-formulas-and-custom-dates-times/842 "2017-08-14T18:35:24Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![wfg-admin](https://yyz2.discourse-cdn.com/flex030/user_avatar/discuss.workflowgen.com/wfg-admin/32/714_2.png) [@wfg-admin](https://discuss.workflowgen.com/u/wfg-admin)\
**Post date:** [August 14, 2017, 6:35pm UTC](https://discuss.workflowgen.com/t/custom-columns-formulas-and-custom-dates-times/842/1 "2017-08-14T18:35:24Z")

</div>

### Formula

The **Formula** tab provides the easiest way to define your computed columns by entering your formula in the expression editor. When you click in the editor, a list of existing columns is displayed.

You can include operators (`*`, `/`, `+`, `-`) and parentheses in your expression.

Press `Enter` to complete the current statement (you will notice that the font is updated and an empty space is added). Note that it is not possible to insert an operator or a column name before a previous statement; you must delete the previous statements first.

You can then use the **Format** list and buttons to adjust the computed column’s format.

#### Validation

After each statement (separated by spaces), a validation module will run to help you ensure that your formula doesn’t contain any errors. As soon as an error is detected, it will be underlined in red and you’ll be prompted to correct it before continuing.

The validation module includes keeping track of parentheses and incompatible operators (`+` followed by `/`), and will ensure that column names are valid. It will also ensure that your formats are compliant with the format of data you’re working with. For example, you cannot use the `Number` format on a column representing date values.

[![custom-columns](https://canada1.discourse-cdn.com/flex030/uploads/workflowgen/original/1X/fe44b8651d112cc495478a1a43e34fc5ccb1b5df.png)  
 ](http://www.workflowgen.com/wp-content/uploads/2016/04/custom-columns.png)

### Custom date & time formats

`d`: the day of the month  
`dd`: the day of the month  
`ddd`: the abbreviated name of the day of the week  
`dddd`: the full name of the day of the week  
`h`: the hour, using a 12-hour clock from 1 to 12  
`hh`: the hour, using a 12-hour clock from 01 to 12  
`H`: the hour, using a 24-hour clock from 0 to 23  
`HH`: the hour, using a 24-hour clock from 00 to 23  
`m`: the minute, from 0 through 59  
`mm`: the minutes,from 00 though 59  
`M`: the month, from 1 through 12  
`MM`: the month, from 01 through 12  
`MMM`: the abbreviated name of the month  
`MMMM`: the full name of the month  
`s`: the second, from 0 through 59  
`ss`: the second, from 00 through 59  
`t`: the first character of the AM/PM designator  
`tt`: the AM/PM designator  
`y`: the year, from 0 to 99  
`yy`: the year, from 00 to 99  
`yyy`: the year, with a minimum of three digits  
`yyyy`: the year as a four-digit number;  
`yyyyy`: the year as a four-digit number.

#### Examples

`dd/MM/yyyy`

`yy.MM.dd`

`dddd dd MMMM yyyy`

`HH:mm ss`

### Resources

For information on computing in JavaScript, see the [Custom columns: JavaScript computing](https://discuss.workflowgen.com/t/custom-columns-javascript-computing/) topic.

For information on custom display functions in JavaScript, see the [Custom columns: JavaScript custom display functions](https://discuss.workflowgen.com/t/custom-columns-javascript-custom-display-functions/) topic.