golden hour

/opt/alt/libicu/usr/include/unicode

File/Folder	Size	Actions
alphaindex.h	26.42 KB
appendable.h	8.43 KB
basictz.h	8.84 KB
brkiter.h	27.53 KB
bytestream.h	9.54 KB
bytestrie.h	19.26 KB
bytestriebuilder.h	7.02 KB
calendar.h	105.06 KB
caniter.h	7.37 KB
casemap.h	25.26 KB
char16ptr.h	7.16 KB
chariter.h	24 KB
choicfmt.h	23.85 KB
coleitr.h	13.7 KB
coll.h	55.59 KB
compactdecimalformat.h	6.81 KB
curramt.h	3.69 KB
currpinf.h	7.24 KB
currunit.h	3.52 KB
datefmt.h	40.37 KB
dbbi.h	1.11 KB
dcfmtsym.h	20.1 KB
decimfmt.h	86.4 KB
docmain.h	6.72 KB
dtfmtsym.h	37.64 KB
dtintrv.h	3.76 KB
dtitvfmt.h	42.87 KB
dtitvinf.h	18.46 KB
dtptngen.h	25.03 KB
dtrule.h	8.62 KB
edits.h	20.67 KB
enumset.h	2.08 KB
errorcode.h	4.78 KB
fieldpos.h	8.63 KB
filteredbrk.h	5.24 KB
fmtable.h	24.36 KB
format.h	12.44 KB
fpositer.h	2.98 KB
gender.h	3.27 KB
gregocal.h	31.57 KB
icudataver.h	1.03 KB
icuplug.h	11.88 KB
idna.h	12.63 KB
listformatter.h	6.18 KB
localpointer.h	16.88 KB
locdspnm.h	7.05 KB
locid.h	44.92 KB
measfmt.h	12.01 KB
measunit.h	38.5 KB
measure.h	4.26 KB
messagepattern.h	33.65 KB
msgfmt.h	43.36 KB
normalizer2.h	33.97 KB
normlzr.h	30.74 KB
nounit.h	2.63 KB
numberformatter.h	87.07 KB
numberrangeformatter.h	28.74 KB
numfmt.h	49.14 KB
numsys.h	6.73 KB
parseerr.h	3.08 KB
parsepos.h	5.45 KB
platform.h	27.1 KB
plurfmt.h	25.18 KB
plurrule.h	17.42 KB
ptypes.h	3.49 KB
putil.h	6.33 KB
rbbi.h	26.41 KB
rbnf.h	49.79 KB
rbtz.h	15.47 KB
regex.h	84.91 KB
region.h	9.12 KB
reldatefmt.h	14.46 KB
rep.h	9.5 KB
resbund.h	18.01 KB
schriter.h	6.26 KB
scientificnumberformatter.h	6.32 KB
search.h	22.21 KB
selfmt.h	14.24 KB
simpleformatter.h	11.43 KB
simpletz.h	45.3 KB
smpdtfmt.h	70.74 KB
sortkey.h	11.12 KB
std_string.h	1015 B
strenum.h	10.04 KB
stringoptions.h	5.79 KB
stringpiece.h	6.46 KB
stringtriebuilder.h	15.27 KB
stsearch.h	21.29 KB
symtable.h	4.21 KB
tblcoll.h	36.4 KB
timezone.h	40.88 KB
tmunit.h	3.29 KB
tmutamt.h	4.8 KB
tmutfmt.h	7.79 KB
translit.h	65.76 KB
tzfmt.h	42.82 KB
tznames.h	16.79 KB
tzrule.h	35.32 KB
tztrans.h	6.07 KB
ubidi.h	89.56 KB
ubiditransform.h	12.65 KB
ubrk.h	23.97 KB
ucal.h	55.2 KB
ucasemap.h	15.18 KB
ucat.h	5.36 KB
uchar.h	139.96 KB
ucharstrie.h	21.06 KB
ucharstriebuilder.h	7.14 KB
uchriter.h	13.14 KB
uclean.h	11.21 KB
ucnv.h	83.09 KB
ucnv_cb.h	6.59 KB
ucnv_err.h	20.99 KB
ucnvsel.h	6.14 KB
ucol.h	61.39 KB
ucoleitr.h	9.46 KB
uconfig.h	11.67 KB
ucpmap.h	5.58 KB
ucptrie.h	22.29 KB
ucsdet.h	14.67 KB
ucurr.h	15.57 KB
udat.h	60.13 KB
udata.h	15.53 KB
udateintervalformat.h	6.79 KB
udatpg.h	26.04 KB
udisplaycontext.h	5.89 KB
uenum.h	7.78 KB
ufieldpositer.h	4.36 KB
uformattable.h	10.94 KB
ugender.h	2 KB
uidna.h	33.37 KB
uiter.h	22.77 KB
uldnames.h	10.45 KB
ulistformatter.h	5.03 KB
uloc.h	50.75 KB
ulocdata.h	11.26 KB
umachine.h	13.19 KB
umisc.h	1.33 KB
umsg.h	24.23 KB
umutablecptrie.h	8.28 KB
unifilt.h	3.63 KB
unifunct.h	3.98 KB
unimatch.h	6.04 KB
unirepl.h	3.32 KB
uniset.h	64.25 KB
unistr.h	174.4 KB
unorm.h	20.45 KB
unorm2.h	24.66 KB
unum.h	53.38 KB
unumberformatter.h	23.76 KB
unumsys.h	7.14 KB
uobject.h	10.7 KB
upluralrules.h	6.72 KB
uregex.h	72.05 KB
uregion.h	9.84 KB
ureldatefmt.h	12.22 KB
urename.h	127.73 KB
urep.h	5.38 KB
ures.h	36.53 KB
uscript.h	26.52 KB
usearch.h	38.12 KB
uset.h	40 KB
usetiter.h	9.49 KB
ushape.h	18 KB
uspoof.h	66.03 KB
usprep.h	8.14 KB
ustdio.h	38.54 KB
ustream.h	1.8 KB
ustring.h	72.47 KB
ustringtrie.h	3.15 KB
utext.h	58.11 KB
utf.h	7.86 KB
utf16.h	22.33 KB
utf32.h	763 B
utf8.h	30.01 KB
utf_old.h	43.78 KB
utmscale.h	13.78 KB
utrace.h	13.89 KB
utrans.h	25.54 KB
utypes.h	30.48 KB
uvernum.h	6.06 KB
uversion.h	6.7 KB
vtzone.h	20.17 KB

Edit: udateintervalformat.h

// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*****************************************************************************************
* Copyright (C) 2010-2012,2015 International Business Machines
* Corporation and others. All Rights Reserved.
*****************************************************************************************
*/

#ifndef UDATEINTERVALFORMAT_H
#define UDATEINTERVALFORMAT_H

#include "unicode/utypes.h"

#if !UCONFIG_NO_FORMATTING

#include "unicode/umisc.h"
#include "unicode/localpointer.h"

/**
 * \file
 * \brief C API: Format a date interval.
 *
 * A UDateIntervalFormat is used to format the range between two UDate values
 * in a locale-sensitive way, using a skeleton that specifies the precision and
 * completeness of the information to show. If the range smaller than the resolution
 * specified by the skeleton, a single date format will be produced. If the range
 * is larger than the format specified by the skeleton, a locale-specific fallback
 * will be used to format the items missing from the skeleton.
 *
 * For example, if the range is 2010-03-04 07:56 - 2010-03-04 19:56 (12 hours)
 * - The skeleton jm will produce
 *   for en_US, "7:56 AM - 7:56 PM"
 *   for en_GB, "7:56 - 19:56"
 * - The skeleton MMMd will produce
 *   for en_US, "Mar 4"
 *   for en_GB, "4 Mar"
 * If the range is 2010-03-04 07:56 - 2010-03-08 16:11 (4 days, 8 hours, 15 minutes)
 * - The skeleton jm will produce
 *   for en_US, "3/4/2010 7:56 AM - 3/8/2010 4:11 PM"
 *   for en_GB, "4/3/2010 7:56 - 8/3/2010 16:11"
 * - The skeleton MMMd will produce
 *   for en_US, "Mar 4-8"
 *   for en_GB, "4-8 Mar"
 * 
 * Note:  the "-" characters in the above sample output will actually be
 * Unicode 2013, EN_DASH, in all but the last example.
 *
 * Note, in ICU 4.4 the standard skeletons for which date interval format data
 * is usually available are as follows; best results will be obtained by using
 * skeletons from this set, or those formed by combining these standard skeletons
 * (note that for these skeletons, the length of digit field such as d, y, or
 * M vs MM is irrelevant (but for non-digit fields such as MMM vs MMMM it is
 * relevant). Note that a skeleton involving h or H generally explicitly requests
 * that time style (12- or 24-hour time respectively). For a skeleton that
 * requests the locale's default time style (h or H), use 'j' instead of h or H.
 *   h, H, hm, Hm,
 *   hv, Hv, hmv, Hmv,
 *   d,
 *   M, MMM, MMMM,
 *   Md, MMMd,
 *   MEd, MMMEd,
 *   y,
 *   yM, yMMM, yMMMM,
 *   yMd, yMMMd,
 *   yMEd, yMMMEd
 *
 * Locales for which ICU 4.4 seems to have a reasonable amount of this data
 * include:
 *   af, am, ar, be, bg, bn, ca, cs, da, de (_AT), el, en (_AU,_CA,_GB,_IE,_IN...),
 *   eo, es (_AR,_CL,_CO,...,_US) et, fa, fi, fo, fr (_BE,_CH,_CA), fur, gsw, he,
 *   hr, hu, hy, is, it (_CH), ja, kk, km, ko, lt, lv, mk, ml, mt, nb, nl )_BE),
 *   nn, pl, pt (_PT), rm, ro, ru (_UA), sk, sl, so, sq, sr, sr_Latn, sv, th, to,
 *   tr, uk, ur, vi, zh (_SG), zh_Hant (_HK,_MO)
 */

/**
 * Opaque UDateIntervalFormat object for use in C programs.
 * @stable ICU 4.8
 */
struct UDateIntervalFormat;
typedef struct UDateIntervalFormat UDateIntervalFormat;  /**< C typedef for struct UDateIntervalFormat. @stable ICU 4.8 */

/**
 * Open a new UDateIntervalFormat object using the predefined rules for a
 * given locale plus a specified skeleton.
 * @param locale
 *            The locale for whose rules should be used; may be NULL for
 *            default locale.
 * @param skeleton
 *            A pattern containing only the fields desired for the interval
 *            format, for example "Hm", "yMMMd", or "yMMMEdHm".
 * @param skeletonLength
 *            The length of skeleton; may be -1 if the skeleton is zero-terminated.
 * @param tzID
 *            A timezone ID specifying the timezone to use. If 0, use the default
 *            timezone.
 * @param tzIDLength
 *            The length of tzID, or -1 if null-terminated. If 0, use the default
 *            timezone.
 * @param status
 *            A pointer to a UErrorCode to receive any errors.
 * @return
 *            A pointer to a UDateIntervalFormat object for the specified locale,
 *            or NULL if an error occurred.
 * @stable ICU 4.8
 */
U_STABLE UDateIntervalFormat* U_EXPORT2
udtitvfmt_open(const char*  locale,
              const UChar* skeleton,
              int32_t      skeletonLength,
              const UChar* tzID,
              int32_t      tzIDLength,
              UErrorCode*  status);

/**
 * Close a UDateIntervalFormat object. Once closed it may no longer be used.
 * @param formatter
 *            The UDateIntervalFormat object to close.
 * @stable ICU 4.8
 */
U_STABLE void U_EXPORT2
udtitvfmt_close(UDateIntervalFormat *formatter);

#if U_SHOW_CPLUSPLUS_API

U_NAMESPACE_BEGIN

/**
 * \class LocalUDateIntervalFormatPointer
 * "Smart pointer" class, closes a UDateIntervalFormat via udtitvfmt_close().
 * For most methods see the LocalPointerBase base class.
 *
 * @see LocalPointerBase
 * @see LocalPointer
 * @stable ICU 4.8
 */
U_DEFINE_LOCAL_OPEN_POINTER(LocalUDateIntervalFormatPointer, UDateIntervalFormat, udtitvfmt_close);

U_NAMESPACE_END

#endif

/**
 * Formats a date/time range using the conventions established for the
 * UDateIntervalFormat object.
 * @param formatter
 *            The UDateIntervalFormat object specifying the format conventions.
 * @param fromDate
 *            The starting point of the range.
 * @param toDate
 *            The ending point of the range.
 * @param result
 *            A pointer to a buffer to receive the formatted range.
 * @param resultCapacity
 *            The maximum size of result.
 * @param position
 *            A pointer to a UFieldPosition. On input, position->field is read.
 *            On output, position->beginIndex and position->endIndex indicate
 *            the beginning and ending indices of field number position->field,
 *            if such a field exists. This parameter may be NULL, in which case
 *            no field position data is returned.
 *            There may be multiple instances of a given field type in an
 *            interval format; in this case the position indices refer to the
 *            first instance.
 * @param status
 *            A pointer to a UErrorCode to receive any errors.
 * @return
 *            The total buffer size needed; if greater than resultLength, the
 *            output was truncated.
 * @stable ICU 4.8
 */
U_STABLE int32_t U_EXPORT2
udtitvfmt_format(const UDateIntervalFormat* formatter,
                UDate           fromDate,
                UDate           toDate,
                UChar*          result,
                int32_t         resultCapacity,
                UFieldPosition* position,
                UErrorCode*     status);

#endif /* #if !UCONFIG_NO_FORMATTING */

#endif