|
1 | 1 | <!-- |
2 | | -$PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.392 2005/10/2515:12:22 momjian Exp $ |
| 2 | +$PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.393 2005/10/2517:54:30 tgl Exp $ |
3 | 3 |
|
4 | 4 | Typical markup: |
5 | 5 |
|
@@ -1147,7 +1147,7 @@ psql -t -f fixseq.sql db1 | psql -e db1 |
1147 | 1147 | SELECT CURRENT_TIMESTAMP AT TIME ZONE 'Europe/London'; |
1148 | 1148 | </programlisting> |
1149 | 1149 | In the above query, the time zone used is adjusted based on the |
1150 | | - daylightsavings time rules that were in effect on the supplied |
| 1150 | + daylightsaving time rules that were in effect on the supplied |
1151 | 1151 | date. |
1152 | 1152 | </para> |
1153 | 1153 | </listitem> |
@@ -1206,21 +1206,22 @@ psql -t -f fixseq.sql db1 | psql -e db1 |
1206 | 1206 |
|
1207 | 1207 | <listitem> |
1208 | 1208 | <para> |
1209 | | - Addan internal day field to <type>INTERVAL</> so a one day |
| 1209 | + Adda separate day field totype<type>interval</> so a one day |
1210 | 1210 | interval can be distinguished from a 24 hour interval (Michael |
1211 | 1211 | Glaesemann) |
1212 | 1212 | </para> |
1213 | 1213 | <para> |
1214 | | - Dates that contain a daylight savings time adjustment are not 24 |
1215 | | - hours, but typically 23 or 25 hours. This change allows numeric days |
1216 | | - (not fixed 24-hour periods) to be added to dates which include |
1217 | | - a daylight savings time adjustment period. Therefore, while in |
1218 | | - previous releases <literal>1 day</> and <literal>24 hours</> were |
1219 | | - interchangeable interval values, in this release they are treated |
1220 | | - differently, e.g. |
| 1214 | + Days that contain a daylight saving time adjustment are not 24 |
| 1215 | + hours long, but typically 23 or 25 hours. This change creates a |
| 1216 | + conceptual distinction between intervals of <quote>so many days</> |
| 1217 | + and intervals of <quote>so many hours</>. Adding |
| 1218 | + <literal>1 day</> to a timestamp now gives the same local time on |
| 1219 | + the next day even if a daylight saving time adjustment occurs |
| 1220 | + between, whereas adding <literal>24 hours</> will give a different |
| 1221 | + local time when this happens. For example, under US DST rules: |
1221 | 1222 | <programlisting> |
1222 | | - '2005-05-03 00:00:00 EST' + '1 day' = '2005-05-04 00:00:00-04' |
1223 | | - '2005-05-03 00:00:00 EST' + '24 hours' = '2005-05-04 01:00:00-04' |
| 1223 | + '2005-04-03 00:00:00-05' + '1 day' = '2005-04-04 00:00:00-04' |
| 1224 | + '2005-04-03 00:00:00-05' + '24 hours' = '2005-04-04 01:00:00-04' |
1224 | 1225 | </programlisting> |
1225 | 1226 | </para> |
1226 | 1227 | </listitem> |
|