He told the Otago board he and his Southland counterpart, Paul Menzies, had agreed on the date, which would have been the Otago board's usual meeting day, and then tossed a coin to determine the venue.
It was going to be challenging fitting the double board and senior executives into the boardroom at the Old Nurses Home at Southland Hospital and some money might have to be spent to "make adjustments", he said.
Depending on how many senior managers attended, there could be up to 30 participants at the meeting.
Member Richard Thomson said they could hire a suitable space for $200.
Mr Millar said they would be looking at other options.
Asked if video-conferencing would be available for members, Mr Millar said he was not ruling out its use, but would rather it was the exception rather than the rule, because it would be complicated with such a large group.
Mr Millar and Mr Menzies were endeavouring to attend each other's board meetings before May so they would be well acquainted with each board's issues, Mr Millar said. Mr Menzies, however, had been unable to attend the Otago meeting yesterday.
Health Minister Tony Ryall has not announced when the new board chairman and deputy will be appointed, but it is understood it may be near to the time of the May meeting.
Reporting on progress towards managing the change to one board, chief regional financial officer Robert Mackway-Jones said one of the matters would be choosing a new logo.
After the meeting, he said he could not give any detail at this stage on how this would be done.
Work had already begun on technical matters including financial reporting, industrial relations issues, information technology, transferring employment to the new organisation and tax arrangements, he told the meeting.
"There is a lot of activity. Most of it is behind-the-scenes stuff."
Mr Millar noted that discussions had already begun with chief executive Brian Rousseau regarding his situation.
He is employed by the Otago board, which has an agreement that he can also work for the Southland board.
The two boards share his salary costs.
The change would mean a change in his terms and conditions, but Mr Millar said he had already indicated to his chief executive "there isn't going to be largesse to distribute".
Another issue which has to be addressed by the boards is who will provide electoral services for the October elections.
Otago has used the Dunedin City Council in the past and Southland the Gore District Council. Both have been asked to come up with a proposal on how they would cover the combined area.
