Issue Summary

When creating an automation with a scheduled trigger, it's impossible to select the “A date” option to execute the rule while trying to run the rule monthly when the current time is the first day of the month

Steps to Reproduce

When the current time is the first date of the month

1. Create an automation with a Scheduled trigger
2. Select the option "Months" (under "Occurrence")
3. Select the field "On the" 
4. Try to select the option "A date"

Expected Results

We should be able to select the "A date" option and continue to configure the rule, as the other options are selectable.

Actual Results

Unable to select the "A date" option. When clicked, the selection is reverted to "First day of month" automatically.

Workaround

Use a cron expression in the "Advanced" tab to run the rule on a specific day of the month (on a monthly basis), or wait one day to create the rule.