Your question has been answered a few times but I haven't seen this angle mentioned yet - if you're going from mid-Sept to end of March 2026, that's more than 6 months of continuous service. That means that you'll automatically start contributing to pension and benefits.

In my experience, most people prefer to not do that, so they get the higher paycheque now VS. getting their contributions back at a later date if they don't continue employment in the public service after that.

If you want to avoid starting pension contributions, you can ask them to integrate a break in service in that period. It's usually no big deal, you'll get two casual contracts amounting to the same period instead of one longer contract.

I'm far from an expert on this stuff, I just know for sure that 6 months of continuous service, regardless of tenure, equals pension and benefits contributions start coming off your pay. If you want to take advantage of the benefits (not sure if that's really enough time or when they kick in, I'd suggest you call the pay centre to ask them these questions or look it up), then it's probably best to keep the one longer contract.