Is herbal tea days before a surgery cause for cancellation?

I am guessing this is ordinary herbal tea and not any special tea with medicinal properties? If you were my patient, I would not cancel surgery on a patient who drank herbal tea. Most herbal teas are essentially for the taste and lack of caffeine without any effects on the body whereas some concentrated herbal supplement pills or powders can have effects on healing or clotting. While I might request that a patient stop certain supplements, I would not cancel surgery for any kind of supplement, because surgery is so important and the side effects of most concerning supplements (increased tendency to bleed) are usually easy to manage and overcome with diligent care and good surgical technique. You should be able to check with your doctors team and I would be surprised if they would be worried or concerned about common herbal tea use.