We present a Stamp\\&Extend time-stamping scheme based on linking via modified creation of Schnorr signatures.
The scheme is based on lazy construction of a tree of signatures.
Stamp\\&Extend returns a timestamp immediately after the request, unlike the schemes based on the concept of timestamping rounds.
Despite the fact that all timestamps are linearly linked, verification of a timestamp requires a logarithmic number of steps with respect to the chain length.
An extra feature of the scheme is that any attempt to forge a timestamp by the Time Stamping Authority (TSA) results in revealing its secret key, providing an undeniable cryptographic evidence of misbehavior of TSA.
Breaking Stamp\\&Extend requires not only breaking Schnorr signatures,
but to some extend also breaking Pedersen commitments.