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utils-std

Collection of commonly available Unix tools git clone https://anongit.hacktivis.me/git/utils-std.git/

date.1.in (3517B)

    

  1. .\" utils-std: Collection of commonly available Unix tools
  2. .\" Copyright 2017 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
  3. .\" SPDX-License-Identifier: MPL-2.0
  4. .Dd April 6, 2025
  5. .Dt DATE 1
  6. .Os
  7. .Sh NAME
  8. .Nm date
  9. .Nd display date and time
  10. .Sh SYNOPSIS
  11. .Nm
  12. .Op Fl jRu
  13. .Op Fl I Ar iso_fmt
  14. .Op Fl d Ar datetime | Fl r Ar epoch
  15. .Op Cm + Ns Ar format
  16. .Nm
  17. .Op Fl jRu
  18. .Op Fl I Ar iso_fmt
  19. .Ar mmddHHMM Ns Oo Oo Ar CC Oc Ns Ar yy Oc
  20. .Op Cm + Ns Ar format
  21. .Nm
  22. .Op Fl jRu
  23. .Op Fl I Ar iso_fmt
  24. .Fl f Ar now_format
  25. .Ar now
  26. .Op Cm + Ns Ar format
  27. .Sh DESCRIPTION
  28. When
  29. .Nm
  30. is invoked without arguments it displays the current datetime
  31. Otherwise, depending on the options specified,
  32. will print the datetime in a user-defined way.
  33. .Sh OPTIONS
  34. .Bl -tag -width Ds
  35. .It Fl d Ar datetime
  36. Use
  37. .Ar datetime
  38. instead of current datetime.
  39. include(lib/iso_parse.mdoc)
  40. .It Fl f Ar now_format
  41. Use
  42. .Ar now_format
  43. as the
  44. .Xr strptime 3
  45. format string for
  46. .Ar now ,
  47. which will be used instead of the current datetime.
  48. .It Fl I Ar iso_fmt
  49. Set the ISO-8601 resolution to format at with setting
  50. .Ar iso_fmt
  51. to one of the following values:
  52. .Bl -tag -width m_inutes_
  53. .It Ar d Ns Op Ar ate
  54. date, equivalent to +%Y-%m-%d
  55. .It Ar h Ns Op Ar ours
  56. hours, equivalent to +%Y-%m-%dT%H%:z
  57. .It Ar m Ns Op Ar inutes
  58. minutes, equivalent to +%Y-%m-%dT%H:%M%:z
  59. .It Ar s Ns Op Ar econds
  60. seconds, equivalent to +%Y-%m-%dT%H:%M:%S%:z
  61. .It Ar n Ns Op Ar s
  62. nano-seconds, equivalent to +%Y-%m-%dT%H:%M:%S,%N%:z
  63. .El
  64. .It Fl j
  65. Do no set the system date.
  66. This allows to use the
  67. .Fl f
  68. flag to convert one datetime to another.
  69. .It Fl u
  70. Use UTC (coordinated universal time) instead of the local time.
  71. .It Fl r Ar epoch
  72. Use
  73. .Ar epoch
  74. (seconds relative to 1970-01-01 00:00:00 UTC)
  75. instead of current datetime.
  76. .It Fl R
  77. Set the default value of
  78. .Ar format
  79. to match RFC5322 (Email / Internet Message Format).
  80. .It Ar mmddHHMM Ns Oo Oo Ar CC Oc Ns Ar yy Oc
  81. Sets custom datetime, if
  82. .Fl j
  83. isn't set, the system time is also set.
  84. .Pp
  85. Each letters corresponds to:
  86. .Bl -tag -width mm -compact
  87. .It mm
  88. months aka %m
  89. .It dd
  90. days aka %d
  91. .It HH
  92. hours aka %H
  93. .It MM
  94. minutes aka %M
  95. .It CC
  96. centuries aka %C
  97. .It yy
  98. century-less years aka %y
  99. .El
  100. .Pp
  101. For example 072505542024 corresponds to 2024-07-25T05:54,
  102. as you can verify with the following command:
  103. .Dl date -j 072505542024 +%Y-%m-%dT%H:%M
  104. .It Cm + Ns Ar format
  105. Set the displayed datetime in
  106. .Xr strftime 3
  107. format,
  108. with additionally
  109. %N for nanoseconds and %:z for colon-separated timezone (±ZZ:ZZ).
  110. .br
  111. Otherwise defaults to
  112. .Ql %c
  113. .El
  114. .Sh ENVIRONMENT
  115. Look at the manual page of
  116. .Xr strftime 3
  117. for the environment variables, typical ones are
  118. .Ev TZ ,
  119. .Ev LC_TIME
  120. and
  121. .Ev LC_ALL
  122. but this depends on your system.
  123. .Sh EXIT STATUS
  124. .Ex -std
  125. .Sh SEE ALSO
  126. .Xr clock_settime 3 ,
  127. .Xr strftime 3
  128. .Sh STANDARDS
  129. .Nm
  130. should be compliant with the
  131. IEEE Std 1003.1-2024 (“POSIX.1”)
  132. specification.
  133. .Pp
  134. The
  135. .Fl d
  136. and
  137. .Fl R
  138. options are present for compatibility with other modern systems such as
  139. NetBSD, BusyBox, and GNU coreutils.
  140. .br
  141. The
  142. .Fl r
  143. option is inspired from BSD and illumos,
  144. .Fl f
  145. and
  146. .Fl j
  147. options are inspired by FreeBSD and NetBSD.
  148. .Pp
  149. The %N and %:z formats are extensions inspired from GNU coreutils.
  150. .Pp
  151. The
  152. .Fl I
  153. option was added for compatibility with GNU coreutils, BusyBox, FreeBSD 12.0+.
  154. .Sh HISTORY
  155. The
  156. .Fl R ,
  157. .Fl d ,
  158. .Fl f ,
  159. .Fl j ,
  160. and
  161. .Fl r
  162. options were present in utils-std 0.0.1.
  163. The
  164. .Fl I
  165. option and %N and %:z formats were added in utils-std 0.0.2.
  166. .Sh AUTHORS
  167. .An Haelwenn (lanodan) Monnier Aq Mt contact+utils@hacktivis.me