PostgreSQL, WIndows, regular backup

Hello.

I would appreciate if someone helps me to resolve this problem about regular backups on Windows. I have a batch file (.bat) for backup, but don't know how to include timestamp in backup file name. In this way I allways have only one, the most recent, backup file. I want Windows to produce regular backups with timestamp in file's name...The script is the following:
pg_dump -f D:\MYDB_BCP -Fc -x -h localhost -U postgres MYDB

How to include timestamp ?