Cannot save date on product attribute when using a locale that changes date format and the day is greater than 12

[bmisyura]

If you add a date attribute to a product or add a date in a product widget and are using a locale that changes the date format and the day set is greater than 12, you get the following error when saving:
Invalid input datetime format of value '14/06/2017'. If you set the date in US english first and then switch to another locale, it displays an incorrect date (when day is greater than 12). If you set a date in US english with day less than 12 and then switch the locale, it shows the original US date format.

Preconditions

1. Install Magento from 2.2-develop branch

Steps to reproduce

1. Go to system>permissions>all users and set the admin user locale to English Australia and save
2. Go to stores>atttributes>products and create a date attribute
3. Go to stores>atttributes>attribute set
4. Add the attribute to default set
5. Create a new product
6. Set the date to any month with the day being greater than 12
7. Try to save
8. Notice the error - Invalid input datetime format of value '14/06/2017

---

1. Go to system>permissions>all users and set the admin user locale to English US and save
2. Go to stores>atttributes>products and create a date attribute
3. Go to stores>atttributes>attribute set
4. Add the attribute to default set
5. Create a new product
6. Set the date to any month with the day being greater than 12 (Feb 14 2018)
7. Save the product
8. Go to system>permissions>all users and set the admin user locale to English Australia and save
9. go back to the product
10. Notice the date is incorrect (06/12/2017)
11. Notice you cannot save the product and error is given "Invalid input datetime format of value '14/02/2018'"

---

1. Go to system>permissions>all users and set the admin user locale to English US and save
2. Go to stores>atttributes>products and create a date attribute
3. Go to stores>atttributes>attribute set
4. Add the attribute to default set
5. Create a new product
6. Set the date to any month with the day being less than 12
7. Save the product
8. Go to system>permissions>all users and set the admin user locale to English Australia and save
9. go back to the product
10. Notice the date is still in US format

The merchant states that this also occurs if you add a date to a product widget

Expected result

The product should save and the dates should be correct when switching the locale after a date is set in US locale

Actual result

The product does not save and gives the error Invalid input datetime format of value '14/06/2017. The date is not correct when switching the locale after a date is set in US locale.

[gwharton]

Heavily related, and possible duplicate of #10580

[ishakhsuvarov]

Closing per comment above.
Thanks for pointing out.