Parameters
Default
Description
date *
--
Valuation date used to select one row of the spot curve table. Only year and month are used; the day is ignored.
t *
--
Duration in years from date. Must be strictly greater than zero.
type
"nominal"
Curve type: nominal, real, or inflation (case-insensitive).
SR_UK("2026-05-31", 10)
Returns the nominal 10-year UK spot rate for May 2026.
SR_UK("2026-05-15", 12.25, "nominal")
Ignores the day, uses the May 2026 nominal curve row, and derives the 12.25-year spot rate from the adjacent forward segment.
SR_UK(A2, B2, "real")
Reads date and duration from worksheet cells and uses the real UK curve.
SR_UK("2026-05-31", 45, "inflation")
For durations beyond the last curve point, extends using the last implied forward segment and converts the result back to a spot rate.
Data source
Reads worksheets spot-curve-nominal, spot-curve-real, and spot-curve-inflation in uk_stats.xlsx.
Date matching
Lookup is by year and month only.
Exact match
If t matches an available duration exactly, the function returns the corresponding spot rate directly.
Short duration rule
If t is smaller than the first available duration, the function returns the first spot rate without forward-rate calculation.
Interpolation rule
If t lies between two durations, the function capitalizes to the lower duration using that spot rate, then applies the forward rate implied by the adjacent spot points, and converts the result back into a spot rate at t.
Extrapolation rule
If t is beyond the last duration, the function uses the last forward segment beyond the final grid point and converts the accumulated value back into a spot rate at t.
Validation
Returns an error if type is invalid, if t is less than or equal to zero, or if the requested year/month is not found.