Php date to timestamp, specifying date to timestamp

Programmers who have written PHP + MySQL know that there is a time difference. The UNIX timestamp and the formatted date are two time representation formats that we often deal with. '2017 08:15:42 ');

Php date to timestamp, specifying date to timestamp

Php date to timestamp, specified date to timestamp, PHP scheduled task.
In the past two days, we need to implement the following functions:
When a certain condition is reached, the server sends a text message to the user. the number of messages is multiple.
Basic idea: scheduled linux Scanning. if a user meets the requirements, the user will send a text message.
However, to prevent disturbing users, you must only send text messages at a.m. during the day. how can you get the daily time range?

The following code:

 = $ Start_time & $ time <= $ end_time) {// do something...}?>