Talks between Government officials and public sector unions on a revised Croke Park agreement on public service pay and conditions have ended for the day.
Informal discussions are due to take place tomorrow.
The Government told unions yesterday that it wants to secure savings of around €170m from payments for working weekends and evenings.
Paul Bell of SIPTU said the talks were at an early stage, but there was a determination to reach a deal on the cost-saving measures presented by the Government.
He said his union was trying to understand what impact the Government proposal to increase public servants working hours by five hours would have on public health service workers and the service they deliver.
Phil Ní Sheaghdha from the Irish Nurses and Midwives Organisation said her union's executive would meet on Monday to examine the progress made so far in the talks.
She said today had been about sharing further information about where savings would come from in the health service.
IMPACT General Secretary Shay Cody said earlier that talks are moving into a much more complex and challenging phase.
Mr Cody said the discussions affect 290,000 people who deliver a whole range of services.
He said when you start changing attendance patterns and terms and conditions it has enormous complex implications and that is what they are working through.
Labour Relations Commission Chief Executive Kieran Mulvey has said he does not think anyone should underestimate the difficulties involved in the talks.
Mr Mulvey said the agenda is very detailed, challenging and difficult, and is probably one of the most challenging areas around the Croke Park deal, since it was signed in 2010.
The Government is seeking €170m in savings from weekend and evening payments.
Under the proposals, the Sunday premium would fall from double time to time-and-a-half.
Payments for working between 6pm and 8pm and for Saturdays would be abolished.
These reductions would hit take-home earnings of significant numbers of public servants, but some could be offset by savings from reducing staff numbers working at weekends and staff working extra hours.
Higher paid public servants face straight pay cuts, although the percentage or the threshold has not been specified.
Unions have called for a higher level of income exempt from the pension levy, and are concerned about the emerging two-tier workforce and outsourcing.