I created a SQL Table with datetime4 as datetime with 2 records:

2018-01-02 11:59:00.000
2018-01-02 12:59:00.000

Using Gridview 9.3A and a DSN pointing to the SQL database I get:

02.01.2018
02.01.2018

in a calculated column I am able to duplicate your issue

02.01.2018
03.01.2018 <== error

Something happening in the formula engine. Will let you know when a "fix" is available.