如何使用PHP将当前时间设置为静态变量？

I need to set the current date and time in static variable.

I need to insert the 50 records into database table. Here,I need to insert the current date and time. Then, I need to set the current date and time of the 50 records are same. I used this  date('Y-m-d H:i:s'); format. This format will change every minutes and seconds.

How to I do. Please help me.

  $date = date('Y-m-d H:i:s')

then use this variable,for create records. All records will have same time.