how to prevent skipping

I an sync on some japanese subs and saw this turns out it skips the first two lines in the sub file I dont get why for reference heres the first few lines

1 00:00:06,172 --> 00:00:08,375 今から100年以上前

2 00:00:09,075 --> 00:00:11,678 人類にある天敵が現れた

3 00:00:16,750 --> 00:00:21,688 彼らと人類の間には 圧倒的な力の差が存在し―

       INFO     Skipped subtitle at index 1: Start time < 0      srt.py:281
                seconds                                                    
       INFO     Skipped subtitle at index 2: Start time < 0      srt.py:281
                seconds