I want to schedule the jasper report in jasper server, with subject name as today date..
Could you clarify your questions please ?
When you say "Subject name" are you refering to the name of the schedule, like resource name of Job name.
It seems quite hard to set this from jasper server gui side. Maybe try to create this via rest api call, you have more flexibility, you can add label and job descriptions. Refer to jasper rest api doc for more info on this.
If you are refering to the output file name , then just tick attribute "Sequential File Names by TimestampTimestamp Pattern".
If you are refering to a label in the report itself, then you can make use of a parameter in a clever way. Add parameter as boolean or something to identify on report side and then if true then set the add today's date to label. Something like that.
Hope this helps, need more clarity on question.
For the scheduler itself, you cannot change the name unfortunately. You can however change the output file name to a date if you would like. If you are sending the report when the scheduler runs, you can also add a subject, which can be your date.