I have not followed your question clearly, I presume there is a change of time that is why Lagan has changed. In any case Mangal dosha is checked from Lagan as well as Moon. If it is Manglik from both then it is a full mangal dosha, if any one then it is Anshik Mangal dosha.
Mangal dosha is formed when Mars is in the 1,4,7,8 & 12 from Lagan and also from Moon. However there are certain exceptions given which cancel or nullify the Mangal dosha. I suggest you read the article How to check Mangal Dosha on AstrologyMag.com and it will give you a good idea how Mangal dosha is formed.
One thing you need to know that if the exceptions are applicable then the Mangal dosha gets cancelled.