Test fails in other timezone

[hpawe01]

When I run the tests on my Windows machine, I get the following error:
Expected '1348-04-06T23:06:32.000Z' to contain '1348-04-07'. The relevant test is it('should return serialized Schools from provided Array of Schools') (https://github.com/ghidoz/angular2-jsonapi/blob/master/projects/angular2-jsonapi/src/converters/json-model/json-model.converter.spec.ts#L139).

I believe the problem is, that my system converts that date other than expected, because I am in another timezone. I can fix this error by using the converted string for comparison:

const c = new DateConverter();
const convertedValue= c.unmask(c.mask(DATA[index].foundation));
expect(element.foundation).toContain(convertedValue);

But I don't know if this the correct way to handle this error or if we could configure the test environment to set a specific timezone.