rj-action-library/Runtime/Shading/Library/Time.gdshaderinc

float timeSine( float _TIME, float duration )
{
  float t = TIME / duration * 2.0 * PI;

  return sin( t );
}

float timeSine01( float _TIME, float duration )
{
  return timeSine( _TIME, duration ) * 0.5 + 0.5;
}