Network maintenance that would have put Twitter offline for as long as 90 minutes yesterday has been postponed due to the importance the microblogging service is currently playing in Iran.
Twitter has emerged as a key route for information both within Iran and between it and other countries following last week's election.
Protestors have taken to the streets after the results were announced and there have been allegations of vote fraud. In response the government has attempted to block access to foreign and independent media outlets sending information into the country.
BBC World Service and other broadcasts are being jammed. The internet, which is channelled through government controlled gateways, is being throttles and mobile phone and messaging networks are being periodically interrupted.
Twitter remains accessible in Iran through proxies.
The maintenance was due to begin at 9:45pm PDT Monday evening, which is 9:15am Tuesday morning in Iran but has been pushed back to 2pm PDT Tuesday (8pm in the UK). The shift means mid-afternoon disruption for millions of Twitter users in the US but translates to an outage at the relatively quieter time of 1:30am Wednesday in Iran.
"Our network partners at NTT America recognise the role Twitter is currently playing as an important communication tool in Iran," wrote co-founder Biz Stone on the company's blog.
Stone praised NTT America, a unit of Japan's NTT Communications, for delaying the work.
"Our partners are taking a huge risk not just for Twitter but also the other services they support worldwide -- we commend them for being flexible in what is essentially an inflexible situation," he wrote.