Based on the Whitepaper found here, logical time is described as:
For this purpose, the creation of an outbound message is considered an atomic event, logically dependent on the previous message created by the same transaction, as well as on the previous transaction of the same account, on the inbound message processed by the same transaction, and on all events contained in the blocks referred to by hashes contained in the block with the same transaction.
As a consequence, outbound messages created by the same smart contract have strictly increasing logical creation times.
In essence, Logical Time is the method by which validators sort transactions and messages logically. Although the key concept is that a higher value of Logical Time will be executed later by the validator.
在同一个合约内的message分发是有内在的时间前后的关系的，在一个执行链路上的若干条message也是有时间前后的关系，这种可以看作逻辑时间
For this purpose, the creation of an outbound message is considered an atomic event, logically dependent on the previous message created by the same transaction, as well as on the previous transaction of the same account, on the inbound message processed by the same transaction, and on all events contained in the blocks referred to by hashes contained in the block with the same transaction.
As a consequence, outbound messages created by the same smart contract have strictly increasing logical creation times.
In essence, Logical Time is the method by which validators sort transactions and messages logically. Although the key concept is that a higher value of Logical Time will be executed later by the validator.
回答2来自: https://answers.ton.org/question/1536842668213014528/how-is-logical-time-generated