"节气"和"杂节"；日本民间采用的历法

                                      “节气”和“杂节”；日本民间采用的历法

      2月4日（前几天就是）是日本历法上的“立春”。“立春” 的意思是/，即 春天的第一天。它是所谓的“二十四节气”之一，这个“二十四节气”的思想来自于古代中国。中国自古以来就使用太阴历，但因太阴历以月亮的盈亏为准，和实际季节会有最大会有半个月的偏差。，所以/故他们也开发出又发明了能反映太阳运动的这个/种历法。

☆从古以来 is correct. But we perfer to use 自 instead 从 in '( )古以来', it is a bit like a fixed thing. And 自 just has the same meaning with 从 here.

☆立春的意思是春天的第一天。

  立春，即春天的第一天。We usually add a comma before 即.

“意味着” seems have the same meaning with my corrections if we translate then into English->

“立春” means 春节的第一天。However, 意味着 let me feel someone has some personal minds when he/she says the thing... But " ‘立春’，即春天的第一天" is a stipulated incident, we don't need to use our personal minds, right... This explain is a little farfetched, so I just advise... because it's just my opinion, and I think 的意思是/，即 sounds better in this sentence...

☆因为……所以……

因……故……

You can also so '因为……故……' and '因……所以'...

But... just... a little... 'split hairs'...

因为 and 所以 both have two characters...

因 and 故 are both single character...

So I think it's better to use '因为……所以……' or '因……故……'