Contrôle Officiel Suisse des Chronomètres (COSC) standards for mechanical chronometer certification is -4 to +6 seconds, or 10 seconds of variation per day, and only around 6% of Swiss-made automatic watches made are certified.
I absolutely have automatics that meet this standard, some of which are COSC certified (my Breitling Chronomat is one) and some that aren't certified but are still this accurate.
If you want to learn more:
http://www.cosc.swiss/en