be up to ninety

To be extremely busy or overworked; to have many things to contend with at once. Primarily heard in Ireland. Sorry I haven't been in touch, but between work and our new baby, I've just been up to ninety lately! We're up to ninety in here, Mary! Could you take this order out to table 10 straight away, please? The phones are ringing off the hook because of that software issue, the flu is going through the department, and our only printer just broke. Yeah, you could say I'm up to ninety right now!