Right now it's not supported, but...
Modern GnuPG (v2.2.42+, v2.4.4+, and v2.5.0+): Fully supports setting and displaying key validity and expiration dates beyond 2038 up to the year 2106 by handling 32-bit/64-bit Epoch time calculations properly.
I think additionally setExpirationDate() should accept objects that implement DateTimeInterface.
ps. on a 32-bit platform the limit seems to be February 7, 2106.
Right now it's not supported, but...
Modern GnuPG (v2.2.42+, v2.4.4+, and v2.5.0+): Fully supports setting and displaying key validity and expiration dates beyond 2038 up to the year 2106 by handling 32-bit/64-bit Epoch time calculations properly.
I think additionally setExpirationDate() should accept objects that implement DateTimeInterface.
ps. on a 32-bit platform the limit seems to be February 7, 2106.