--- order: 2 --- # 日期时间 我们可以使用 `time` 包来创建一个 `DateTime` 对象。 ## 使用 ```nv let t = time.parse("2023-04-13 09:45:26") // t is a DateTime object t.year // 2023 t.month // 4 t.day // 13 let t1 = time.parse("invalid time") // t1 is nil ``` ## 类方法 ### new 创建一个新的 DateTime 对象。 ```nv let t = time.new(2023, 1, 11, 0, 0, 0); // t is a DateTime object export let t_str = t.to_string(); // t_str is "2023-01-11T00:00:00Z" ``` ### parse (time) 解析一个字符串为 DateTime 对象，默认时间格式为 [RFC3339]。 如果时间格式无效，将返回 `nil`。 如果字符串内没有包含时区信息，将会默认采用 `UTC` 时区。 ```nv let t = time.parse("2023-04-13T14:08:33-11:00"); ``` 或者也兼容支持 `%Y-%m-%d %H:%M:%S` 格式。 ```nv let t = time.parse("2023-04-13 09:45:26"); ``` ### parse (time, format) 你可以采用 `parse` 方法传递两个参数，第一个是时间字符串，第二个是时间格式。 ```nv time.parse("2023-04-13 09:45:26", "%Y-%m-%d %H:%M:%S"); time.parse("2023-04-13 09:45:26", "%Y-%m-%d %H:%M:%S %z"); time.parse("04/13/2023 09:45:26", "%m/%d/%Y %H:%M:%S"); ``` 更多细节的时间格式，参见 [Time Format]。 ## 实例方法 ### year 返回时间的年份。 ```nv let t = time.parse("2023-04-13 09:45:26") t.year // 2023 ``` ### month 返回月份。 ```nv let t = time.parse("2023-04-13 09:45:26"); t.month; // 4 ``` ### day 返回时间的日期。 ```nv let t = time.parse("2023-04-13 09:45:26"); t.day; // 13 ``` ### hour 返回时间的小时。 ```nv let t = time.parse("2023-04-13 09:45:26"); t.hour; // 9 ``` ### minute 返回时间的分钟。 ```nv let t = time.parse("2023-04-13 09:45:26"); t.minute; // 45 ``` ### second 返回时间的秒数。 ```nv let t = time.parse("2023-04-13 09:45:26"); t.second; // 26 ``` ### timestamp 返回时间的 Unix 时间戳（秒）格式的数字。 ```nv let t = time.parse("2023-04-13 09:45:26 +08:00"); t.timestamp; // 1681350326 ``` ### format 基于参数的 [Time Format] 返回时间字符串。 ```nv let t = time.parse("2023-04-13 09:45:26 +08:00"); t.format("%Y-%m-%d %H:%M:%S %z"); // 2023-04-13 09:45:26 +0800 t.format("%m/%d/%Y %H:%M"); // 04/13/2023 09:45 ``` ### iso8601 > alias: [to_string](#to_string) 返回时间字符串，格式为 [RFC3339]。 ```nv let t = time.parse("2023-04-13 09:45:26 +08:00"); t.iso8601; // 2023-04-13T09:45:26+08:00 ``` ### to_string > alias: [iso8601](#iso8601) 返回时间字符串，格式为 [RFC3339]。 ## Time Format | Code | Example | Description | | ---- | ------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `%a` | `Sun` | Weekday as locale’s abbreviated name. | | `%A` | `Sunday` | Weekday as locale’s full name. | | `%w` | `0` | Weekday as a decimal number, where 0 is Sunday and 6 is Saturday. | | `%d` | `08` | Day of the month as a zero-padded decimal number. | | `%b` | `Sep` | Month as locale’s abbreviated name. | | `%B` | `September` | Month as locale’s full name. | | `%m` | `09` | Month as a zero-padded decimal number. | | `%y` | `13` | Year without century as a zero-padded decimal number. | | `%Y` | `2013` | Year with century as a decimal number. | | `%H` | `07` | Hour (24-hour clock) as a zero-padded decimal number. | | `%I` | `07` | Hour (12-hour clock) as a zero-padded decimal number. | | `%p` | `AM` | Locale’s equivalent of either AM or PM. | | `%M` | `06` | Minute as a zero-padded decimal number. | | `%S` | `05` | Second as a zero-padded decimal number. | | `%f` | `000000` | Microsecond as a decimal number, zero-padded on the left. | | `%z` | `+0000` | UTC offset in the form ±HHMM\[SS\[.ffffff\]\] (empty string if the object is naive). | | `%Z` | `UTC` | Time zone name (empty string if the object is naive). | | `%j` | `251` | Day of the year as a zero-padded decimal number. | | `%U` | `36` | Week number of the year (Sunday as the first day of the week) as a zero padded decimal number. All days in a new year preceding the first Sunday are considered to be in week 0. | | `%W` | `35` | Week number of the year (Monday as the first day of the week) as a decimal number. All days in a new year preceding the first Monday are considered to be in week 0. | | `%c` | `Sun Sep 8 07:06:05 2013` | Locale’s appropriate date and time representation. | | `%x` | `09/08/13` | Locale’s appropriate date representation. | | `%X` | `07:06:05` | Locale’s appropriate time representation. | | `%%` | `%` | A literal `%` character. | [rfc3339]: https://tools.ietf.org/html/rfc3339 [time format]: #time-format [unix timestamp]: https://en.wikipedia.org/wiki/Unix_time