These are the variants available in LocalTime, notice MIDNIGHT and MIN are equal.

LocalDate.now().atTime(LocalTime.MIDNIGHT); //00:00:00.000000000
LocalDate.now().atTime(LocalTime.MIN);      //00:00:00.000000000
LocalDate.now().atTime(LocalTime.NOON);     //12:00:00.000000000
LocalDate.now().atTime(LocalTime.MAX);      //23:59:59.999999999

For reference, this is the implementation in java.time.LocalTime

/**
 * Constants for the local time of each hour.
 */
private static final LocalTime[] HOURS = new LocalTime[24];
static {
    for (int i = 0; i < HOURS.length; i++) {
        HOURS[i] = new LocalTime(i, 0, 0, 0);
    }
    MIDNIGHT = HOURS[0];
    NOON = HOURS[12];
    MIN = HOURS[0];
    MAX = new LocalTime(23, 59, 59, 999_999_999);
}

If the value assigned to the 4th constructor argument (999_999_999) of LocalTime (representing nanoOfSecond) looks unfamiliar it's because it's making use of the Java 7 feature Underscores in Numeric Literals.

In Java SE 7 and later, any number of underscore characters (_) can appear anywhere between digits in a numerical literal. This feature enables you, for example, to separate groups of digits in numeric literals, which can improve the readability of your code.

These are the variants available in LocalTime, notice MIDNIGHT and MIN are equal.

LocalDate.now().atTime(LocalTime.MIDNIGHT); //00:00:00.000000000
LocalDate.now().atTime(LocalTime.MIN);      //00:00:00.000000000
LocalDate.now().atTime(LocalTime.NOON);     //12:00:00.000000000
LocalDate.now().atTime(LocalTime.MAX);      //23:59:59.999999999

For reference, this is the implementation in java.time.LocalTime

/**
 * Constants for the local time of each hour.
 */
private static final LocalTime[] HOURS = new LocalTime[24];
static {
    for (int i = 0; i < HOURS.length; i++) {
        HOURS[i] = new LocalTime(i, 0, 0, 0);
    }
    MIDNIGHT = HOURS[0];
    NOON = HOURS[12];
    MIN = HOURS[0];
    MAX = new LocalTime(23, 59, 59, 999_999_999);
}

If the value assigned to the 4th constructor argument (999_999_999) of LocalTime (representing nanoOfSecond) looks unfamiliar it's because it's making use of the Java 7 feature Underscores in Numeric Literals.

In Java SE 7 and later, any number of underscore characters (_) can appear anywhere between digits in a numerical literal. This feature enables you, for example, to separate groups of digits in numeric literals, which can improve the readability of your code.

These are the variants available in LocalTime, notice MIDNIGHT and MIN are equal.

LocalDate.now().atTime(LocalTime.MIDNIGHT); //00:00:00.000000000
LocalDate.now().atTime(LocalTime.MIN);      //00:00:00.000000000
LocalDate.now().atTime(LocalTime.NOON);     //12:00:00.000000000
LocalDate.now().atTime(LocalTime.MAX);      //23:59:59.999999999

For reference, this is the implementation in java.time.LocalTime

/**
 * Constants for the local time of each hour.
 */
private static final LocalTime[] HOURS = new LocalTime[24];
static {
    for (int i = 0; i < HOURS.length; i++) {
        HOURS[i] = new LocalTime(i, 0, 0, 0);
    }
    MIDNIGHT = HOURS[0];
    NOON = HOURS[12];
    MIN = HOURS[0];
    MAX = new LocalTime(23, 59, 59, 999_999_999);
}

These are the variants available in LocalTime, notice MIDNIGHT and MIN are equal.

LocalDate.now().atTime(LocalTime.MIDNIGHT); //00:00:00.000000000
LocalDate.now().atTime(LocalTime.MIN);      //00:00:00.000000000
LocalDate.now().atTime(LocalTime.NOON);     //12:00:00.000000000
LocalDate.now().atTime(LocalTime.MAX);      //23:59:59.999999999

For reference, this is the implementation in java.time.LocalTime

/**
 * Constants for the local time of each hour.
 */
private static final LocalTime[] HOURS = new LocalTime[24];
static {
    for (int i = 0; i < HOURS.length; i++) {
        HOURS[i] = new LocalTime(i, 0, 0, 0);
    }
    MIDNIGHT = HOURS[0];
    NOON = HOURS[12];
    MIN = HOURS[0];
    MAX = new LocalTime(23, 59, 59, 999_999_999);
}

If the value assigned to the 4th constructor argument (999_999_999) of LocalTime (representing nanoOfSecond) looks unfamiliar it's because it's making use of the Java 7 feature Underscores in Numeric Literals.

In Java SE 7 and later, any number of underscore characters (_) can appear anywhere between digits in a numerical literal. This feature enables you, for example, to separate groups of digits in numeric literals, which can improve the readability of your code.