Do you mean "IT" as in the people who deal with technical issues / supplies that the company is facing (they might be working in shifts). Another way to use "IT" is to refer to the whole group of people who operate computers on a more than user level, but mostly including people who'd self-identify as programmers.

If you mean the former, then yeah, these people might work in shift, but usually don't (they might work in shifts only if the organization they support needs 24 hour technical support, or NOC, as I've already mentioned), which most organization don't need. This technical support interpretation of IT is very rarely programming anything (exceptions are SREs or PEs in large companies where there's so much complexity in their in-house infrastructure that they need tech support to program).

In the later case, there's no need for most of IT to work in shifts. Definitely not at night. Same way how there's no need for accountants to work in shifts (and definitely not at night).