NSDateを5分刻み・15分刻みで丸める

NsDateを初期値としてUIDatePicker等に設定する場合、日付の丸め処理が必要になるのでメモ。

NsDateを5分間隔で丸める処理

+ (NSDate *)round5Minites:(NSDate *)date
{
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setLocale:[NSLocale systemLocale]];
    [formatter setDateFormat:@"m"];
    int ref = [[formatter stringFromDate:date] intValue];
    if (ref % 5 != 0)
    {
        float def = round(ref * 0.1f) * 10;
        if(def < ref) def += 5;
        date = [date dateByAddingTimeInterval:60 * (def - ref)];
    }
    return date;
}

NsDateを15分間隔で丸める処理

+ (NSDate *)round15Minites:(NSDate *)date
{
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setLocale:[NSLocale systemLocale]];
    [formatter setDateFormat:@"mm"];
    int minutes = [[formatter stringFromDate:date] intValue];
    [formatter setDateFormat:@"ss"];
    int seconds = [[formatter stringFromDate:date] intValue];
    int remain = minutes % 15;
    return [date dateByAddingTimeInterval:-(60 * remain) - seconds];
}

以上。