witching hour?

i love love love the nighttimes and early mornings with my 12 day old baby boy. At night its quiet, just me and him (im a single mom and my mom leaves us at night so that i learn). He feeds quietly while i watch something on low volume, then i burp him, change his diaper and feed him again just to doze off. he usually lasts a good 4 hours during the night. then 3pm to about 7pm come and my baby is a different person! hes fussy, he wants to nurse for hours and hours, hes never satisfied, barely sleeps and cries like hes starving, even though hes drained the boobs. i have no idea what to do. then 8pm comes along once hes relaxed from his bath and hes lovely again. any tips? is this his witching hour(s)? am i doing something wrong during the day? is he just distracted or interested in other things? i have no idea. my mom is usually a mine of information but shes at a loss as well.