Struct ExcelDateTime 

pub struct ExcelDateTime { /* private fields */ }

Structure for Excel date and time representation.

Implementations

impl ExcelDateTime

pub fn new(value: f64, datetime_type: ExcelDateTimeType, is_1904: bool) -> Self

Creates a new ExcelDateTime

pub fn is_duration(&self) -> bool

True if excel datetime has duration format ([hh]:mm:ss, for example)

pub fn is_datetime(&self) -> bool

True if excel datetime has datetime format (not duration)

pub fn as_f64(&self) -> f64

Converting data type into a float

pub fn to_ymd_hms_milli(&self) -> (u16, u8, u8, u8, u8, u8, u16)

Convert an Excel serial datetime to standard date components.

Datetimes in Excel are serial dates with days counted from an epoch (usually 1900-01-01) and where the time is a percentage/decimal of the milliseconds in the day. Both the date and time are stored in the same f64 value. For example, 2025/10/13 12:00:00 is stored as 45943.5.

This function returns a tuple of (year, month, day, hour, minutes, seconds, milliseconds). It works for serial dates in both the 1900 and 1904 epochs.

This function always returns a date, even if the serial value is outside of Excel’s range of 0.0 <= datetime < 10000.0. It also returns, as Excel does, the invalid date 1900/02/29 due to the Excel 1900 leap year bug.

Excel only supports millisecond precision and it also doesn’t use or encode timezone information in any way.

Examples

An example of converting an Excel date/time to standard components.

use calamine::{ExcelDateTime, ExcelDateTimeType};

// Create an Excel datetime from the serial value 45943.541 which is
// equivalent to the date "2025/10/13 12:59:02.400".
let excel_datetime = ExcelDateTime::new(
    45943.541,
    ExcelDateTimeType::DateTime,
    false, // Using 1900 epoch (not 1904).
);

// Convert to standard date/time components.
let (year, month, day, hour, min, sec, milli) = excel_datetime.to_ymd_hms_milli();

assert_eq!(year, 2025);
assert_eq!(month, 10);
assert_eq!(day, 13);
assert_eq!(hour, 12);
assert_eq!(min, 59);
assert_eq!(sec, 2);
assert_eq!(milli, 400);

pub fn as_duration(&self) -> Option<Duration>

Available on crate feature chrono only.

Try converting data type into a duration.

pub fn as_datetime(&self) -> Option<NaiveDateTime>

Available on crate feature chrono only.

Try converting data type into a datetime.

Trait Implementations

impl Clone for ExcelDateTime

fn clone(&self) -> ExcelDateTime

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ExcelDateTime

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ExcelDateTime

fn default() -> Self

Returns the “default value” for a type.

impl Display for ExcelDateTime

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl PartialEq for ExcelDateTime

fn eq(&self, other: &ExcelDateTime) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for ExcelDateTime

impl StructuralPartialEq for ExcelDateTime