Created
November 21, 2012 08:28
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ISO8601 to unix timestamp
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-module(iso8601_to_unixtimestamp). | |
-define(GREGORIAN_SECONDS_TO_UNIXTIMESTAMP_DIFFERENCE, 719528*24*3600). | |
-export([doit/0]). | |
parse_iso8601(DateString) -> | |
{ok,[Year, Month, Day, Hour, Min, Sec],_} = io_lib:fread("~d-~d-~dT~d:~d:~dZ", DateString), | |
{{Year,Month,Day},{Hour,Min,Sec}}. | |
ymdhms_to_gregorian_seconds({{Year,Month,Day},{Hour,Min,Sec}}) -> | |
calendar:datetime_to_gregorian_seconds({{Year,Month,Day},{Hour,Min,Sec}}). | |
gregorian_seconds_to_unixtimestamp(Seconds) -> | |
Seconds - ?GREGORIAN_SECONDS_TO_UNIXTIMESTAMP_DIFFERENCE. | |
convert_unixtimestamp_to_timestamp(UnixTimestamp) -> | |
{UnixTimestamp div 1000000000000, | |
UnixTimestamp div 1000000 rem 1000000, | |
UnixTimestamp rem 1000000}. | |
timestamp_to_unixtimestamp({MegaSecs, Secs, MicroSecs}) -> | |
MegaSecs * 1000000 * 1000000 + Secs * 1000000 + MicroSecs. | |
doit() -> | |
ISO8601 = "2012-11-21T09:00:00Z", | |
io:fwrite("ISO8601: ~s~n", [ISO8601]), | |
DateTime = parse_iso8601(ISO8601), | |
io:fwrite("DateTime: ~p~n", [DateTime]), | |
GregorianSeconds = ymdhms_to_gregorian_seconds(DateTime), | |
io:fwrite("GregorianSeconds: ~p~n", [GregorianSeconds]), | |
UnixTimestamp = gregorian_seconds_to_unixtimestamp(GregorianSeconds), | |
io:fwrite("UnixTimestamp: ~p~n", [UnixTimestamp]), | |
Timestamp = convert_unixtimestamp_to_timestamp(UnixTimestamp), | |
io:fwrite("Timestamp: ~p~n", [Timestamp]), | |
UnixTimestamp2 = timestamp_to_unixtimestamp(Timestamp), | |
io:fwrite("UnixTimestamp2: ~p~n", [UnixTimestamp2]), | |
UnixTimestamp =:= UnixTimestamp2. |
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1> iso8601_to_unixtimestamp:doit().
ISO8601: 2012-11-21T09:00:00Z
DateTime: {{2012,11,21},{9,0,0}}
GregorianSeconds: 63520707600
UnixTimestamp: 1353488400
Timestamp: {0,1353,488400}
UnixTimestamp2: 1353488400
true
2>