Editorial: Align FormatDateTimePattern mathematical comparison with editorial conventions (#1080)

Author: gibson042

spec/datetimeformat.html

@@ -1401,9 +1401,9 @@ <h1>
             1. If _partType_ is *"month"*, set _value_ to _value_ + 1.
             1. If _partType_ is *"hour"* and _dateTimeFormat_.[[HourCycle]] is *"h11"* or *"h12"*, then
               1. Set _value_ to _value_ modulo 12.
-              1. If _value_ is 0 and _dateTimeFormat_.[[HourCycle]] is *"h12"*, set _value_ to 12.
+              1. If _value_ = 0 and _dateTimeFormat_.[[HourCycle]] is *"h12"*, set _value_ to 12.
             1. If _partType_ is *"hour"* and _dateTimeFormat_.[[HourCycle]] is *"h24"*, then
-              1. If _value_ is 0, set _value_ to 24.
+              1. If _value_ = 0, set _value_ to 24.
             1. If _fieldFormat_ is *"numeric"*, then
               1. Let _formattedValue_ be FormatNumeric(_nf_, _value_).
             1. Else if _fieldFormat_ is *"2-digit"*, then