How many hours from Texas to New York city by flight?

That would vary greatly on where in Texas you are departing from because of the size of that State. Here are a few examples:

Texarkana - 22 hours and 25 minutes.

Beaumont - 25 hours.

Dallas - 25 hours.

San Antonio - 30 hours.

Amarillo - 28 hours.

Brownsville - 32 hours.

El Paso - 35 hours.

All times as estimated courtesy of google Maps.