# `Calendrical.InvalidOptionValueError`

Exception returned, or raised by a calendar maker, when an option is given
a value it cannot take: an unknown `:day_start`, a `:nightfall_angle` that
is not a number, a `:location` that is not a place, or a calendar maker's
option in a form it does not take.

### Fields

* `:option` — the option that was given.

* `:value` — the value it was given.

* `:maker` — the calendar maker the option was given to, such as
  `Calendrical.Calendar.Weeks`, or `nil` for a function's option.

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*Consult [api-reference.md](api-reference.md) for complete listing*