A deal involving a derivative contract whose maturity date is not associated with a standard maturity (reference point). Banks usually quote forward rates for specific standard maturities such as 1, 2, 3, .., 12 months. Deals in derivative contracts whose maturities dates don’t coincide with the ends of whole time periods (weeks, months, years) are dubbed broken date deals. For example, a bank may offer a swap with a non-standard maturity of two years and 293 days.

Rates for such deals are typically computed by interpolating between two standard dates. Normally, two-way prices are quoted for each of these dates. The bank may serve a customer wishing to deal for a broken date by accepting to offer a quote calculated by adding to the nearest reference point a premium or discount based on the implicit forward-forward rate between that date and the nearest reference date on the other side of the broken date.