This could be a condition known as EVENING COLIC where a baby cries due to abdominal pain
. The crying episodes are mostly in the evening between 6pm to 10pm.The pain can be mild causing just restlessness
or it can be severe with rhythmical screaming attacks lasting for a few minutes and alternating with quiet periods.Commonly seen in this age group and can go on for about 3 months of age. Nobody knows why this happens. Sometimes relief might be obtained by making the baby lie on his/her stomach( prone position) and after passing gas. As a mother, avoid eating milk, egg, wheat and nuts for a couple of days and see if there is any difference in the baby's crying. For the baby, Try to use gentle rhythmic movements to relax the baby, or try using a pacifier, or make the baby listen to some soft soothing music. Evening colic is nothing to worry about. It will go away on its own after some time and the condition should stop by the time baby is 3 months old.
There are so many conditions where babies cry incessantly. This could be anything mild from( nappy rash, wet napkin, napkin pin poking the baby,hunger, thirst, heat ,cold ) to serious infections( ear infection
, urinary tract infection
It would be best to take your baby to the paediatrician as the doctor can do a thorough assessment of the baby . Hope your baby gets well soon :)))