[tz] Historical discrepancies for Italy.

Brian Inglis Brian.Inglis at SystematicSw.ab.ca
Fri Oct 21 20:31:34 UTC 2016


On 2016-10-20 15:27, Pierpaolo Bernardi wrote:
> about Italian time, I see:
> # From Paul Eggert (2006-03-22):
> # For Italian DST we have three sources: Shanks & Pottenger, Whitman, and
> # F. Pollastri
> # Day-light Saving Time in Italy (2006-02-03)
> # http://toi.iriti.cnr.it/uk/ienitlt.html
> # ('FP' below), taken from an Italian National Electrotechnical Institute
> # publication. When the three sources disagree, guess who's right, as follows:
> I don't know about the other sources, but:
> - the url given to cnr.it is dead.
> - The authoritative source for time in Italy is the national
> metrological institute, which has a summary page of historical DST
> data at http://www.inrim.it/res/tf/ora_legale_i.shtml
> - Some of the data in TZ does not agree with this page.
> I think that there must be VERY strong evidence that the INRIM is
> wrong before preferring other sources?

Hi Pierpaolo,

That page does not cite any of its sources:
- some of them could be those used in the tzdb or the tzdb itself;
- tzdb prefers official government sources as references, better if viewable
   online;
- perhaps you could contact INRIM to find out if they can provide references
   to information of which the list was not previously aware?

Also perhaps you (or they) could say what the phrases:
"dalle ore X del" and "alle ore X estive del"
mean in this context?
Google Translate says they mean something like:
"from hour X" and "from summer time hour X",
implying local (standard or daylight) time is used in both cases.

I have attached comparisons of the data from the table on the web page,
converted by scripts to tzdb rules, flagged with i in the Type column
relabelled Src, and conversions of those date/times showing 24:00 to the next
date 00:00, flagged with =, both with the day of the week appended to the day
in the month, for easier checking.
Those were merged with tzdb Italy rules, flagged with z.

Comparison was done visually and entries where there are discrepancies have a
? appended to the end of the tzdb line; sometimes others where I thought data
may be questionable.
Some assumptions were made in the comparison:
- web page times are local standard time for daylight start entries and local
   daylight time for daylight end entries;
- daylight start entries with the same time value with or without s (standard
   time suffix) are the same;
- daylight end entries with local time an hour later than an entry in standard
   time are the same: entries with the same time value with and without s
   (standard time suffix) differ;
- there may be more/fewer discrepancies if these assumptions are wrong.

Some tabs between leading columns were converted to spaces to shrink line
length for attachment.

If you contact INRIM, please feel free to forward the comparison.

Scripts used and intermediate files are available by email if anyone cares.

-- 
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
-------------- next part --------------
# Rule NAME FROM TO Src IN ON dow	AT	SAVE	LETTER/S
Rule Italy 1916 only i Jun  3 Sat	24:00	1:00	S
Rule Italy 1916 only = Jun  4 Sun	00:00	1:00	S
Rule Italy 1916 only z Jun  3		0:00s	1:00	S	?

Rule Italy 1916 only i Sep 30 Sat	24:00	0   	-
Rule Italy 1916 only = Oct  1 Sun	00:00	0   	-
Rule Italy 1916 only z Oct  1		0:00s	0	-	?

Rule Italy 1917 only i Mar 31 Sat	24:00	1:00	S
Rule Italy 1917 only = Apr  1 Sun	00:00	1:00	S
Rule Italy 1917 only z Apr  1		0:00s	1:00	S

Rule Italy 1917 only i Sep 30 Sun	24:00	0   	-	?
Rule Italy 1917 only = Oct  1 Mon	00:00	0   	-	?
Rule Italy 1917 only z Sep 30		0:00s	0	-	?

Rule Italy 1918 only i Mar  9 Sat	24:00	1:00	S
Rule Italy 1918 only = Mar 10 Sun	00:00	1:00	S
Rule Italy 1918 only z Mar 10		0:00s	1:00	S

Rule Italy 1918 only i Oct  6 Sun	24:00	0   	-	?
Rule Italy 1918 only = Oct  7 Mon	00:00	0   	-	?
Rule Italy 1918 1919 z Oct Sun>=1	0:00s	0	-	?

Rule Italy 1919 only i Mar  1 Sat	24:00	1:00	S
Rule Italy 1919 only = Mar  2 Sun	00:00	1:00	S
Rule Italy 1919 only z Mar  2		0:00s	1:00	S

Rule Italy 1919 only i Oct  4 Sat	24:00	0   	-
Rule Italy 1919 only = Oct  5 Sun	00:00	0   	-
Rule Italy 1918 1919 z Oct Sun>=1	0:00s	0	-	?

Rule Italy 1920 only i Mar 20 Sat	24:00	1:00	S
Rule Italy 1920 only = Mar 21 Sun	00:00	1:00	S
Rule Italy 1920 only z Mar 21		0:00s	1:00	S

Rule Italy 1920 only i Sep 18 Sat	24:00	0   	-
Rule Italy 1920 only = Sep 19 Sun	00:00	0   	-
Rule Italy 1920 only z Sep 19		0:00s	0	-	?

Rule Italy 1940 only i Jun 14 Fri	24:00	1:00	S
Rule Italy 1940 only = Jun 15 Sat	00:00	1:00	S
Rule Italy 1940 only z Jun 15		0:00s	1:00	S

Rule Italy 1942 only i Nov  2 Mon	24:00	0   	-
Rule Italy 1942 only = Nov  3 Tue	00:00	0   	-
Rule Italy 1942 only z

Rule Italy 1943 only i Mar 29 Mon	02:00	1:00	S
Rule Italy 1943 only z

Rule Italy 1943 only i Oct  4 Mon	03:00	0   	-
Rule Italy 1943 only z

Rule Italy 1944 only i Apr  3 Mon	02:00	1:00	S
Rule Italy 1944 only z

Rule Italy 1944 only i Sep 17 Sun	02:00	0   	-
Rule Italy 1944 only z Sep 17		0:00s	0	-	?

Rule Italy 1945 only i Apr  2 Mon	02:00	1:00	S
Rule Italy 1945 only z Apr  2		2:00	1:00	S

Rule Italy 1945 only i Sep 15 Sat	01:00	0   	-
Rule Italy 1945 only z Sep 15		0:00s	0	-

Rule Italy 1946 only i Mar 17 Sun	02:00	1:00	S
Rule Italy 1946 only z Mar 17		2:00s	1:00	S	?

Rule Italy 1946 only i Oct  6 Sun	03:00	0   	-
Rule Italy 1946 only z Oct  6		2:00s	0	-

Rule Italy 1947 only i Mar 16 Sun	00:00	1:00	S
Rule Italy 1947 only z Mar 16		0:00s	1:00	S

Rule Italy 1947 only i Oct  5 Sun	01:00	0   	-
Rule Italy 1947 only z Oct  5		0:00s	0	-	?

Rule Italy 1948 only i Feb 29 Sun	02:00	1:00	S
Rule Italy 1948 only z Feb 29		2:00s	1:00	S

Rule Italy 1948 only i Oct  3 Sun	03:00	0   	-
Rule Italy 1948 only z Oct  3		2:00s	0	-

Rule Italy 1966 only i May 22 Sun	00:00	1:00	S
Rule Italy 1966 1968 z May Sun>=22	0:00	1:00	S

Rule Italy 1966 only i Sep 24 Sat	24:00	0   	-
Rule Italy 1966 only = Sep 25 Sun	00:00	0   	-
Rule Italy 1966 1969 z Sep Sun>=22	0:00	0	-

Rule Italy 1967 only i May 28 Sun	00:00	1:00	S
Rule Italy 1966 1968 z May Sun>=22	0:00	1:00	S

Rule Italy 1967 only i Sep 24 Sun	01:00	0   	-
Rule Italy 1966 1969 z Sep Sun>=22	0:00	0	-	?

Rule Italy 1968 only i May 26 Sun	00:00	1:00	S
Rule Italy 1966 1968 z May Sun>=22	0:00	1:00	S

Rule Italy 1968 only i Sep 22 Sun	01:00	0   	-
Rule Italy 1966 1969 z Sep Sun>=22	0:00	0	-	?

Rule Italy 1969 only i Jun  1 Sun	00:00	1:00	S
Rule Italy 1969 only z Jun  1		0:00	1:00	S

Rule Italy 1969 only i Sep 28 Sun	01:00	0   	-
Rule Italy 1966 1969 z Sep Sun>=22	0:00	0	-	?

Rule Italy 1970 only i May 31 Sun	00:00	1:00	S
Rule Italy 1970 only z May 31		0:00	1:00	S

Rule Italy 1970 only i Sep 27 Sun	01:00	0   	-
Rule Italy 1970 only z Sep lastSun	0:00	0	-	?

Rule Italy 1971 only i May 23 Sun	00:00	1:00	S
Rule Italy 1971 1972 z May Sun>=22	0:00	1:00	S

Rule Italy 1971 only i Sep 26 Sun	01:00	0   	-
Rule Italy 1971 only z Sep lastSun	1:00	0	-

Rule Italy 1972 only i May 28 Sun	00:00	1:00	S
Rule Italy 1971 1972 z May Sun>=22	0:00	1:00	S

Rule Italy 1972 only i Oct  1 Sun	01:00	0   	-
Rule Italy 1972 only z Oct  1		0:00	0	-	?

Rule Italy 1973 only i Jun  3 Sun	00:00	1:00	S
Rule Italy 1973 only z Jun  3		0:00	1:00	S

Rule Italy 1973 only i Sep 30 Sun	01:00	0   	-
Rule Italy 1973 1974 z Sep lastSun	0:00	0	-	?

Rule Italy 1974 only i May 26 Sun	00:00	1:00	S
Rule Italy 1974 only z May 26		0:00	1:00	S

Rule Italy 1974 only i Sep 29 Sun	01:00	0   	-
Rule Italy 1973 1974 z Sep lastSun	0:00	0	-	?

Rule Italy 1975 only i Jun  1 Sun	00:00	1:00	S
Rule Italy 1975 only z Jun  1		0:00s	1:00	S

Rule Italy 1975 only i Sep 28 Sun	01:00	0   	-
Rule Italy 1975 1977 z Sep lastSun	0:00s	0	-

Rule Italy 1976 only i May 30 Sun	00:00	1:00	S
Rule Italy 1976 only z May 30		0:00s	1:00	S

Rule Italy 1976 only i Sep 26 Sun	01:00	0   	-
Rule Italy 1975 1977 z Sep lastSun	0:00s	0	-

Rule Italy 1977 only i May 22 Sun	00:00	1:00	S
Rule Italy 1977 1979 z May Sun>=22	0:00s	1:00	S

Rule Italy 1977 only i Sep 25 Sun	01:00	0   	-
Rule Italy 1975 1977 z Sep lastSun	0:00s	0	-

Rule Italy 1978 only i May 28 Sun	00:00	1:00	S
Rule Italy 1977 1979 z May Sun>=22	0:00s	1:00	S

Rule Italy 1978 only i Oct  1 Sun	01:00	0   	-
Rule Italy 1978 only z Oct  1		0:00s	0	-

Rule Italy 1979 only i May 27 Sun	00:00	1:00	S
Rule Italy 1977 1979 z May Sun>=22	0:00s	1:00	S

Rule Italy 1979 only i Sep 30 Sun	01:00	0   	-
Rule Italy 1979 only z Sep 30		0:00s	0	-



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