VBA Date & Time issue

 so the above VB Code above says that if cells A, B and C are completed, then in Cell D the date and Time is added in the format "DD/MM/YYYY hh:mm:ss AM/PM"

but for the first 12 days of the month the format is "MM/DD/YYYY" but once it turns the 13th, it corrects itself as if it finally registers as a month?

so for example.  tomorrow it'll say 07/02/2021.  but on the 13th it'll say 13/07/2021.

Thanks in advance for any help with this.  it's been bugging me for months 😛

D_Jones1994