Hi,
Couple of thing..
1st. Check you ABAP time zone STZAC and java time zone in configtool and if required correct it.
2nd. Seems your JAVA systems GC algo is not working - Again check config tool. Check heap dump generated in server0 directory. Also, provide us your system configuration and memory parameter set in configtool.
Also, Please upload std_server0 and dispatcher.out files
Regards,
DV