To bring a watch "to time " means to make it keep correct time. To do so with a good watch, the curb pins must first be closed until the hairspring has no play between them. Then regulate by lengthening or shortening the hairspring, the regulator meanwhile being kept in the centre. Shortening the hairspring makes the watch go faster and rice versa. After each alteration of the hairspring, the watch must be set in beat afresh by turning the hairspring collet round a little.