How to best inform users that a monthly process includes today

Question

I have a dropdown where a user can select a date they want they want to auto pay their bills every month. For example, if they choose the 12th, every 12th day of the month they will be charged for the balance on their account. How do I best inform users that if they choose the 11th and today is 11th that their account will be charged today?

Answer 1

Consider replacing the dropdown – which is simple to implement but less intuitive for date data – with a more natural calendar widget that pops up the current month, wherein the current day is distinguished visually (both color and marker for visual accessibility).

Try prototyping that solution.

Then, if it proves to not feel right in your case, use the prototype as a reference point and increment the dropdown 'towards' that solution. The calendar widget will expand your thinking and will suggest new ideas.

Perhaps the dropdown list items can be given more structure. Possibilities include: the current day can be separated by non-selectable delineations, given a css color, amended with the label of "today" with a typographic variance.

Once a selection is made, generate a plain language summation with special case:

Your bill will be paid on the 11th of every month. 
(!) Your first payment will occur immediately today.

Answer 2

Next to your drop down, add the date of the first payment and the number of days from now.

For example:

Day of month: [ 11 ]
First payment: May 11, 2018 (today)

Day of month: [ 12 ]
First payment: May 12, 2018 (tomorrow)

Day of month: [ 10 ]
First payment: June 10, 2018 (in 30 days)

If one of the choices will cause the user to pay separately for the current cycle in order to avoid being late, prefer a default value that isn't one of these choices, and consider alerting the user if they make one of these choices, for example:

Day of month: [ 10 ]
First payment: June 10, 2018 (in 30 days)
Warning: your account will be past due by then.
[Start today instead]