Hi, I'm a beginner and next week I'll try to begin trading at IB with a margin account. I don't have too many funds to buy several contracts for covered call writing, so I want to set up Long Calendar Spreads with call options, but I'd like to be sure how margin works for this spread contruction. I heard that Calendar Spreads are purchased in a margin account, but no margin requirements is necessary because, theoretically, the purchased option has a longer life than the written option. What do I have to do if my short calls is exercised in an automated trading environment like IB? And what will the broker act after this? Thank you!