The husband of Nazanin Zaghari-Ratcliffe, a British women imprisoned in Tehran, said he is still optimistic his wife will be home for Christmas.
Richard Ratcliffe said Foreign Secretary Boris Johnson has made every effort during his two-day visit to Iran, with "positive consequences from that".
Mr Johnson has been seeking the release of Mrs Zaghari-Ratcliffe as he held top-level talks in Tehran with Iranian president Hassan Rouhani and foreign minister Mohammad Javad Zarif.
With the postponement of a new court case against his wife, which came as a result of Mr Johnson's trip, Mr Ratcliffe said the weekend has been positive, but there is a risk of him over reading it all.
"We were fearing a bad day and we haven't had that, which makes it a good day. I guess we will see what the next few days mean," he told the Press Association.
"But it feels like it a really good sign, almost like we have a momentum - we have had a couple of things that have been positive over the weekend."
Alongside his wife not appearing in court, she has also seen a psychiatrist and the propaganda pedalled against her through Iranian media has subsided, Mr Ratcliffe said.
He added: "It is all movement, it doesn't change the fundamentals but it makes the change in the fundamentals more likely."
Having always been keen to have his wife home for Christmas and for her birthday which follows soon after, he said he is optimistic that this is still achievable.
"But as Christmas gets closer it gets harder to expect," he added. "I wasn't presuming that she would come back on the plane with him.
"So I think for me, it was always best case scenario that his going would unlock the door and then days later she might be able to come home.
"That is still possible, she has still got that application for early release, she has still got a medical assessment - all those things that were hanging there on the good side are still there.
"The bad stuff that was hanging there seems a bit more remote, the good stuff feels like it is more and more likely to go ahead.
"Of course the bad stuff is still possible, and the good stuff is still not guaranteed, but the balance has shifted."
Asked what he would say to those who may suggest Mr Johnson has failed in not bringing Mrs Zaghari-Ratcliffe on the plane with him, Mr Ratcliffe said it was "always going to be tricky".
"But it looks to me like he is making every effort that he can - and it looks like there have been positive consequences from that," he added.
Mr Ratcliffe said that until December 24 comes he is "certainly hopeful" of his wife coming home, and added: "This weekend has given me more cause for hope, not less.
"Let's us hope the days to come are equally as good, and if they are, then yes she will be home for Christmas - but of course they might not be.
"So I do need to reserve some energy in case I need to go again."