rename span to timeSpan

Signed-off-by: Tomas Neme <lacrymology@gmail.com>
assume the timeSpan parameter is received in minutes

Signed-off-by: Tomas Neme <lacrymology@gmail.com>
make sure we don't mix the received paramter with the generated window

Signed-off-by: Tomas Neme <lacrymology@gmail.com>