I had interviews with this company at the end of May, and after 3 rounds, they offered me the job at the beginning of June. I have 3 months notice (until 30.September), so it means I will start at my new job on 01. October.
During the interviews, they asked me if I could start earlier. I told them I was not sure because of 3 months period. They sent me the contract already, which will start on 01. October. I signed it and sent it back to them and I already got the Welcome New Member Email from the company.
I talked with my Team Lead if I can terminate the contract earlier (it's a rule/right at my current company). He said yes, there was a possibility. I then informed new company that there's a possibility I could start earlier, and asked how early they would want me to start. And they replied that 01. August and asked me to confirm them again so they can send me a new contract.
But it seems that I can't go earlier, because the current company asked me if I could stay until the end of September, to help them set up the new project. I have a good relationship with my current company, so I said yes. Besides, I already signed the new contract which will start on 01.October.
Now, I wonder if I would create a bad image of myself in new company's eyes when I tell them that now I can't start earlier. I know, the new company is my future and I should focus on them, and I really want to start with them earlier. But at the same time, I just couldn't leave my current employer a big gap, without substitute. Especially they already asked me the favour.
How can I tell my new company (HR person) that I will start as the original contract stated, in a way that I don't sound like an annoying new employee? And is it normal to start a new job that late? I mean, it's the end of June, and October sounds like a long way ahead. I am afraid they would lose interest in me.
Thanks for any advice.