Douglas Council says opening the splash park three weeks earlier each summer would be too expensive because it would have to pay staff extra.
The local authority's Regeneration and Community committee discussed the issue at its last meeting, when it was suggested the facility in Noble's Park opened on Friday, May 1 instead of Saturday, May 23.
Councillors heard the splash park is run by staff working overtime, and bringing its opening forward would cost £1,500.
They voted to keep the current schedule and review the decision in a year's time.
Report shows growth in government workforce
Can you translate Filipino for court?
Commissioner worried over Ramsey flood wall design
AG's chambers wrongly blocked FOI response, says info commissioner
Navy ship off Island's coast
'Harrods of the West' to reopen in April
Mountain Road closed on 68 days last year
Terry’s Tato’s owner named 2026 Customer Service Champion