keep span length

Signed-off-by: Tomas Neme <lacrymology@gmail.com>
don't check only for existence

Signed-off-by: Tomas Neme <lacrymology@gmail.com>
check that { from, timeSpan } are correctly handled

Signed-off-by: Tomas Neme <lacrymology@gmail.com>
parameter timeSpan comes in minutes, not ms!

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