====== Save datetime of randomization ======

You can automatically save the time of randomization, or any other  status change, using the **@CALCDATE** action tag.  This tag lets you calculate a new date that is offset from an existing date.  In this case, the existing date is "//now//" and the offset is zero.  The following text can be entered as the **Action Tags/Field Annotation** for a text box field type.  The variable **randomized_arm** should be replaced with the randomization field as configured on the project, and **randomized_date** should be replaced with the variable name that is tracking the datetime of randomization. 

<code>
@READONLY
@CALCDATE(if([randomized_arm] != '' and [randomized_date] = '', 'now', [randomized_date]), 0, 'd')
</code>