I verbally promised to a big company company that I'd be able to join in a month (the date they had in mind), then I realized that it'd be hard to do so before I finish my grad school (nearly impossible with a full-time job, and delaying is not an option!). Fortunately, the offer letter doesn't specify any start date, so I signed it!
Now, I'm worried what to say when they ask for start date (probably via a separate document yet to be signed).
The team seemed laid back, looking to fill more than a single position, and it's a big company (>10K employees), so would it be risky to shift it by 2 months right away? Or would it make more sense to shift it 4-6 weeks first, then an additional 2-4 weeks later? Which strategy would minimize the risk of the company rescinding the offer?