Saturday's meeting at Navan has been postponed due to the forecast of adverse weather conditions.
The Proudstown circuit was due to play host to a seven-race card, featuring the Grade Three Flyingbolt Novice Chase.
However, with a Status Yellow wind warning in place from Met Eireann, the fixture has been cancelled for safety reasons.
The Irish Horseracing Regulatory Board said details on rescheduling the meeting would follow in due course.
Officials at Chepstow have made the decision to call off Monday's card due to waterlogging.
The track had been hit by 25 millimetres of rain on Friday up to around 3pm and with heavy rain forecast over the weekend and no significant improvement envisaged, the team decided to make an early call.