Happy Half-Tau Day to those who write their dates middle endian (MM/DD/YYYY).
The attached patch allows you to enter literal numbers using the One True Circle Constant, the ratio of circumference to radius, tau:
1t1 -: 2p1
1p1 -: 0.5t1
For motivation, refer to the excellent "Tau Manifesto" by Michael Hartl:
Monadic o. continues to multiply by the impostor ratio pi (circumference to diameter) and will remain a historical curiosity.
Round and round, turn by turn,
Remington