Daylight Savings and Time Zone Settings

The Survox phone system handles records that do not observe daylight savings time by “moving” them one time zone to the west when the phone file is set to DAYLIGHT_SAVINGS=YES. For instance, Arizona phone numbers are in the Mountain Time Zone (Survox TZ=7). During the Winter time they are treated as Mountain Standard Time (MST), but when the rest of the USA moves their clocks forward in the Spring, those numbes are moved into Survox Time Zone 8 and are treated the same as Pacific Daylight Time numbers. The Time Zone setting in columns 23-24 is actually changed from 07 to 08.

The following 4 fields in the record control how this is handled.

20.1 – If this is a D in the raw sample record, then the record will be treated as not observing Daylight Savings. This is mostly for dealing with International numbers that do not observe Daylight Savings, but could also be used for NANPA numbers as well. This is only in the raw sample record and will not be in the actual phone record.

23.2 – Is the 2 digit number which represents the “effective” time zone using the following schema. 24 is Greenwich Mean Time. The time zone to the west is 1 and each subsequent zone to the west is incremented by 1, up to 24. Time zones to the east of GMT are decremented by 1. Time zones 5, 6, 7, and 8 are respectively Eastern, Central, Mountain, and Pacific times in North America. Time zones 22, 23, and 24 are respectively for Eastern Europe, Western Europe, and the UK. Half time zones are dealt with by using a letter (A-X) to stand for the time zone in column 23 and a 5 in column 24. A5 would be timezone 1.5, B5 is 2.5, and so on. See the article on setting up International dialing for more information about how to make sure you set the correct time zone for those numbers.

5110.1 – Will be a 1 if the record does not observe Daylight Savings otherwise it is a 0. This is usually set when Fonebuld reads the zonetable entry for the incoming record, but can also be set by having a D in column 20 on the raw record.

5397.3 – Is a 3 digit number that represents the “actual” time zone the phone numbers is in. For “normal” time zones the first 2 digits match the schema for 23.2 and the last digit is a 0. For half time zones, the first 2 digits will follow the normal numbering schema and the last digit will be a 5.

For records that observe daylight savings 23.2 and 5397.2 will match. For records that do not observe daylight savings 23.2 and 5397.2 will match when the DAY_LIGHT_SAVINGS=NO, but 2.3 will be 1 higher than 5397.2 when DAY_LIGHT_SAVINGS=YES.

Here are some examples of what happens.

The phone number is 415-555-1234 which is a CA number that observes DST.

If you add that number into the file, then 23.2= 08, 5110=0 and 5397.3=080 no matter what the DAY_LIGHT_SAVINGS time switch is set to.

The phone number is 602-555-1234 which is an AZ number that does NOT observe DST.

If you add that number in the file when DAY_LIGHT_SAVINGS=NO, then 23.2=07, 5110=1, and 5397.3=070.
However, if you add that number in the file when DAY_LIGHT_SAVINGS=YES, then 23.2=08, 5110=1, and 5397.3=070.

If you have a file that has been built, but the files were not properly marked as non-daylight records, you can use the attached Mentor spec file to adjust them. You will need to delete the records out of your current file, then run the spec to adjust them, and then lastly add them back in using the ASCII option in Fonebuld.

  • daylight_convert.spx