Try using to progressive disclosure to reveal the reminder when they enter the birthday option.

Since the birthday is optional, having the extra 'reminder' control is unnecessary (and potentially confusing) if they won't fill out the control on which it's dependent upon.

Why not take advantage of interaction flow and time, revealing the element only once the user has chosen to enter a birthday? This will reveal the relationship between the birthday and the reminder:

I'm not sure about your use case, but I used a checkbox control to allow them to opt-in. It does mean it's another click for the user, but it allows them to feel like they're giving explicit permission in this case.

Try using to progressive disclosure to reveal the reminder when they enter the birthday option.

Since the birthday is optional, having the extra 'reminder' control is unnecessary (and potentially confusing) if they won't fill out the control on which it's dependent upon.

Why not take advantage of interaction flow and time, revealing the element only once the user has chosen to enter a birthday? This will reveal the relationship between the birthday and the reminder:

Updated option: What if it's important to surface the feature?

@bloodyKnuckles brings up a fair point about hinting at a feature in order to encourage its use.

In that case, I'm still holding off the complete interaction until they enter the birthday field. My thoughts are that seeing a disabled, negative state (like the 'Never' dropdown) cause more friction, that a checkbox 'opt-in' that enables for possible completion once the birthday is entered.

I'm not sure about your use case, but I used a checkbox control to allow them to opt-in. It does mean it's another click for the user, but it allows them to feel like they're giving explicit permission in this case.

Try using to progressive disclosure to reveal the reminder when they enter the birthday option.

Since the birthday is optional, having the extra 'reminder' control is unnecessary (and potentially confusing) if they won't fill out the control on which it's dependent on.

Why not take advantage of interaction flow and time, revealing the element only once the user has chosen to enter a birthday?

I'm not sure about your use case, but I used a checkbox control to allow them to opt-in. It does mean it's another click for the user, but it allows them to feel like they're giving explicit permission in this case.

Try using to progressive disclosure to reveal the reminder when they enter the birthday option.

Since the birthday is optional, having the extra 'reminder' control is unnecessary (and potentially confusing) if they won't fill out the control on which it's dependent upon.

Why not take advantage of interaction flow and time, revealing the element only once the user has chosen to enter a birthday? This will reveal the relationship between the birthday and the reminder:

I'm not sure about your use case, but I used a checkbox control to allow them to opt-in. It does mean it's another click for the user, but it allows them to feel like they're giving explicit permission in this case.