Where to find it: Add new Content or double-click a Content item, then go to Content Details panel > Header > Delay:
The dynamic delay feature allows you to set content publishing delays using attributes or variables instead of a static value.
Any smartword can be used but the value of the smartword held must represent a time (not a date & time or some other value).
If the Project attribute “int_delay” is an Integer, you must use Time Functions on that attribute to indicate the delay you want:

Note: You can’t use SECONDS with dynamic delays.

You can also parse an integer and then use that inside a Time function. For example:
|parse(‘integer’) as delay_var|

Of course, if you use an attribute that is a Time attribute then you can use the attribute directly without the Time functions:

“Delay” in this example is a Time attribute.

Set specific time of day
The format of time is the following: hh:mm:ss, so you need to indicate the hour of the day you’d like the message to be sent (from 00:00:00 to 23:59:00).
For example, let’s use an audience time attribute, delay
If you want to send the email at 1pm, the time attribute value must be 13:00:00.

 Note: you could also transform an integer value into a time variable. 
 audience.delay = |HOURS(13)|
 The value of audience.delay will be 00:13:00.