date.md

---

date: 2020-10-20T09:26:21+08:00 # 创建日期 author: "Rustle Karl" # 作者

文章

title: "date 打印或者设置系统日期和时间" # 文章标题

description: "文章描述"

url: "posts/linux/tools/standard/date" # 设置网页永久链接 tags: [ "linux", "cmd" ] # 标签 series: [ "Linux 学习笔记" ] # 系列 categories: [ "学习笔记" ] # 分类

章节

weight: 20 # 排序优先级 chapter: false # 设置为章节

index: true # 是否可以被索引 toc: true # 是否自动生成目录 draft: false # 草稿

打印或者设置系统日期和时间

格式

date [OPTION]... [+FORMAT]
date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]

参数

参数	作用
-d, --date = STRING	display time described by STRING, not 'now'
-f, --file = DATEFILE	like --date once for each line of DATEFILE
-r, --reference = FILE	display the last modification time of FILE
2-R, --rfc -2822334	output date and time in RFC 2822 format. Example: Mon, 07 Aug 2006 12:34:56 -0600
--rfc -3339 = TIMESPEC	output date and time in RFC 3339 format. TIMESPEC = 'date', 'seconds', or 'ns' for date and time to the indicated precision. Date and time components are separated by a single space: 2006 -08 -07 12:34:56 -06:00
-s, --set = STRING	set time described by STRING
-u, --utc, --universal	print or set Coordinated Universal Time
--help	display this help and exit
--version	output version information and exit

备注

• --date=STRING 可以是自由格式的可读性良好的日期字符串，比如 Sun, 29 Feb 2004 16:21:42 -0800、2004-02-29 16:21:42、next Thursday。一个日期字符串可能包含年月日、时分秒、时区、星期、相对日期等。空字符串表示一天的开始。
• export TZ=[INT] 可以设置时区环境变量，未设置情况下从 /etc/localtime 中获取。

export TZ=0
date
Wed Jan  8 06:00:14  2020

格式化输出

占位符	含义
%%	a literal %
%a	locale's abbreviated weekday name (e.g., Sun)
%A	locale's full weekday name (e.g., Sunday)
%b	locale's abbreviated month name (e.g., Jan)
%B	locale's full month name (e.g., January)
%c	locale's date and time (e.g., Thu Mar 3 23:05:25 2005)
%C	century ; like %Y, except omit last two digits (e.g., 20)
%d	day of month (e.g, 01)
%D	date ; same as %m/%d/%y
%e	day of month, space padded ; same as %_d
%F	full date ; same as %Y-%m-%d
%g	last two digits of year of ISO week number (see %G)
%G	year of ISO week number (see %V) ; normally useful only with %V
%h	same as %b
%H	hour (00..23)
%I	hour (01..12)
%j	day of year (001..366)
%k	hour ( 0..23)
%l	hour ( 1..12)
%m	month (01..12)
%M	minute (00..59)
%n	a newline
%N	nanoseconds (000000000..999999999)
%p	locale's equivalent of either AM or PM ; blank if not known
%P	like %p, but lower case
%r	locale's 12-hour clock time (e.g., 11:11:04 PM)
%R	24-hour hour and minute ; same as %H:%M
%s	seconds since 1970 -01 -01 00:00:00 UTC
%S	second (00..60)
%t	a tab
%T	time ; same as %H:%M:%S
%u	day of week (1..7) ; 1 is Monday
%U	week number of year, with Sunday as first day of week (00..53)
%V	ISO week number, with Monday as first day of week (01..53)
%w	day of week (0..6) ; 0 is Sunday
%W	week number of year, with Monday as first day of week (00..53)
%x	locale's date representation (e.g., 12/31/99)
%X	locale's time representation (e.g., 23:13:48)
%y	last two digits of year (00..99)
%Y	year
%z	+hhmm numeric timezone (e.g., -0400)
%:z	+hh:mm numeric timezone (e.g., -04:00)
%::z	+hh:mm:ss numeric time zone (e.g., -04:00:00)
%:::z	numeric time zone with : to necessary precision (e.g., -04, +05:30)
%Z	alphabetic time zone abbreviation (e.g., EDT)
By default, date pads numeric fields with zeroes. The following optional flags may follow '%':
-	(hyphen) do not pad the field
_	(underscore) pad with spaces
0	(zero) pad with zeros
^	use upper case if possible
#	use opposite case if possible

示例

1. 默认格式输出当前时间

date
Wed Jan  8 13:32:00 CST 2020

2. 格式化输出当前时间

date +"%Y-%m-%d %H:%M:%S"
2020-01-08 13:32:43

date +"%Y.%m.%d %H:%M:%S"
2020.01.08 13:33:39

3. 修改系统时间

date -s "20191201 8:30:00"
Sun Dec  1 08:30:00 CST 2019

date
Sun Dec  1 08:30:03 CST 2019

4. 输出某天是当年第几天

date +%j
335

date -d '20200106 8:30:00' +%j
006

4. 时间戳转换

# 输出当前时间戳
date +%s
1578461371

# 指定时间转换时间戳
date -d '2019-12-27T17:38:04' +%s
1577439484

5. 同步网络时间

ntpdate 0.asia.pool.ntp.org
8 Jan 13:45:19 ntpdate[7501]: step time server 202.21.176.62 offset 3301728.210931 sec

date
Wed Jan  8 13:45:30 CST 2020