Time

isDST()

Since 0.6.0:

Returns true if Daylight Saving Time (DST) is in effect.

// Print true or false depending on whether the DST in in effect
Serial.print(Time.isDST());

Returns: Unsigned 8-bit integer: 0 = false, 1 = true

This function only returns the current DST setting that you choose using beginDST() or endDST(). The setting does not automatically change based on the calendar date.