When a test runs over a period of two days, the log_match() should automatically read from the correct day log file if starttime is not passed as an argument. There are many test cases that do not pass starttime explicitly. If those tests run close to the day boundaries they might fail. we have to update log_match to set starttime default to the test start time if starttime is not passed. It is users responsibility to overwrite it inside the test.
Also if number of lines required are more than in the previous day log than log_match will also open the next day log to find the texts. For example, test started at 11:58pm and prints something at 12:01 while log_match is called at 12:03am. log_match then concatenate both the logs to look for the match.