SIARD-->SQL-->SIARD: Validation of SIARD fails due lacking "Z" in DATE-type values after export

[ibbenz]

Description of error:
I execute a import-export cycle with a SIARD-file and check finally if the data remained the same.
However, DATE-type values are changed during this cycle, which results in a validation-error in the dbptk-validator.
I attached the exported file to this issue.

DATE in the imported SIARD-file (table6, column 18): 0001-01-01Z
DATE in the exported SIARD-file (table3, column 18) 0001-01-01

dbptk-validation of the exported file:
T_6.0-2: [ERROR] - Validation against XSD failed. - cvc-minInclusive-valid: Value '0001-01-01' is not facet-valid with respect to minInclusive '0001-01-01Z' for type 'dateType'. At line 1,

The bug disappears, when I manually change the 0001-01-01 to 0001-01-01Z in the SIARD file.
I attached the corrected file to this issue (see 2.4b_1-3_Northwind_simple_220913_B_b.zip)
Why is the "Z" truncated during the Export?

Steps required to reproduce the bug:

1. Open 0_1-3_Northwind_simple_220913_B_dbptk.siard and load it into a Microsoft SQL-Database
2. Download the uploaded DATA in a new SIARD File 2.4b_1-3_Northwind_simple_220913_B.siard
3. Validate the downloaded SIARD-file

The imported SIARD-file:
0_1-3_Northwind_simple_220913_B_dbptk.zip

The exported SIARD-file:
2.4b_1-3_Northwind_simple_220913_B.zip

The exported SIARD-file and "Z" added in column 18 of table 3:
2.4b_1-3_Northwind_simple_220913_B_b.zip

Attach the dbptk-app.log.txt file below.
dbvtk.log