Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

add note about microsecond precision in Calendar.strftime #14137

Merged
merged 3 commits into from
Jan 4, 2025
+18 −1
Merged

add note about microsecond precision in Calendar.strftime #14137

Changes from 2 commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
0572bef
add note about microsecond precision in Calendar.strftime
simonmcconnell Jan 2, 2025
9e9a6a4
explain in more detail and add examples
simonmcconnell Jan 2, 2025
fa205fd
move microseconds examples to the end
simonmcconnell Jan 4, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
71 changes: 44 additions & 27 deletions lib/elixir/lib/calendar.ex
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -496,38 +496,55 @@ defmodule Calendar do

The accepted formats for `string_format` are:

Format | Description | Examples (in ISO)
:----- | :-----------------------------------------------------------------------| :------------------------
a | Abbreviated name of day | Mon
A | Full name of day | Monday
b | Abbreviated month name | Jan
B | Full month name | January
c | Preferred date+time representation | 2018-10-17 12:34:56
d | Day of the month | 01, 31
f | Microseconds *(does not support width and padding modifiers)* | 000000, 999999, 0123
H | Hour using a 24-hour clock | 00, 23
I | Hour using a 12-hour clock | 01, 12
j | Day of the year | 001, 366
m | Month | 01, 12
M | Minute | 00, 59
p | "AM" or "PM" (noon is "PM", midnight as "AM") | AM, PM
P | "am" or "pm" (noon is "pm", midnight as "am") | am, pm
q | Quarter | 1, 2, 3, 4
s | Number of seconds since the Epoch, 1970-01-01 00:00:00+0000 (UTC) | 1565888877
S | Second | 00, 59, 60
u | Day of the week | 1 (Monday), 7 (Sunday)
x | Preferred date (without time) representation | 2018-10-17
X | Preferred time (without date) representation | 12:34:56
y | Year as 2-digits | 01, 01, 86, 18
Y | Year | -0001, 0001, 1986
z | +hhmm/-hhmm time zone offset from UTC (empty string if naive) | +0300, -0530
Z | Time zone abbreviation (empty string if naive) | CET, BRST
% | Literal "%" character | %
Format | Description | Examples (in ISO)
:----- | :----------------------------------------------------------------------- | :------------------------
a | Abbreviated name of day | Mon
A | Full name of day | Monday
b | Abbreviated month name | Jan
B | Full month name | January
c | Preferred date+time representation | 2018-10-17 12:34:56
d | Day of the month | 01, 31
f | Microseconds (uses its precision for width and padding) | 000000, 999999, 0123
H | Hour using a 24-hour clock | 00, 23
I | Hour using a 12-hour clock | 01, 12
j | Day of the year | 001, 366
m | Month | 01, 12
M | Minute | 00, 59
p | "AM" or "PM" (noon is "PM", midnight as "AM") | AM, PM
P | "am" or "pm" (noon is "pm", midnight as "am") | am, pm
q | Quarter | 1, 2, 3, 4
s | Number of seconds since the Epoch, 1970-01-01 00:00:00+0000 (UTC) | 1565888877
S | Second | 00, 59, 60
u | Day of the week | 1 (Monday), 7 (Sunday)
x | Preferred date (without time) representation | 2018-10-17
X | Preferred time (without date) representation | 12:34:56
y | Year as 2-digits | 01, 01, 86, 18
Y | Year | -0001, 0001, 1986
z | +hhmm/-hhmm time zone offset from UTC (empty string if naive) | +0300, -0530
Z | Time zone abbreviation (empty string if naive) | CET, BRST
% | Literal "%" character | %
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Can we please make sure we only change a single row in the table? :) Thank you!


Any other character will be interpreted as an invalid format and raise an error.

### `%f` Microseconds

`%f` does not support width and padding modifiers. It will be formatted by truncating
the microseconds to the precision of the `microseconds` field of the struct, with a
minimum precision of 1.

## Examples

Microsecond formatting:
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Let's move this to the end or middle of examples, we should not start with it. :)


iex> Calendar.strftime(~U[2019-08-26 13:52:06Z], "%y-%m-%d %H:%M:%S.%f")
"19-08-26 13:52:06.0"

iex> Calendar.strftime(~U[2019-08-26 13:52:06.048Z], "%y-%m-%d %H:%M:%S.%f")
"19-08-26 13:52:06.048"

iex> Calendar.strftime(~U[2019-08-26 13:52:06.048531Z], "%y-%m-%d %H:%M:%S.%f")
"19-08-26 13:52:06.048531"

Without user options:

iex> Calendar.strftime(~U[2019-08-26 13:52:06.0Z], "%y-%m-%d %I:%M:%S %p")
Expand Down