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![Parsing Temporal Instant from ISO 8601 string
â—Ź datetime($string), localdatetime($string), date($string), time($string), localtime($string)
â—Ź date: YYYY-MM-DD, or YYYY-Www-D, or YYYY-Qq-DD, or YYYY-DDD
(calendar date, week date, quarter date, ordinal date respectively)
â—‹ dashes can be omitted, smaller units can be omitted
â—‹ year with a sign prefix can be arbitrarily long, but then dashes may not be omitted
â—Ź time: HH:MM:SS.sss
â—‹ colons can be omitted, smaller units can be omitted
● offset: ±HH:MM or Z
â—‹ colons can be omitted, smaller units can be omitted
â—Ź zone: [name]](https://image.slidesharecdn.com/ocig7-2018-03-14-cip2015-08-06dateandtime-180315115036/85/Supporting-dates-and-times-in-Cypher-6-320.jpg)
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Supporting dates and times in Cypher
- 1. Date and Time CIP2015-08-06
- 2. Temporal instant types â—ŹDateTime â—‹ with timezone (logical zone or absolute offset from UTC) â—Ź LocalDateTime â—‹ without timezone â—Ź Date â—‹ without timezone â—Ź Time â—‹ with absolute offset from UTC (logical zones needs date to map to offset) â—Ź LocalTime â—‹ without timezone
- 3. Duration type â—Ź Representsa number of â—‹ years â—‹ months â—‹ days â—‹ hours â—‹ minutes â—‹ seconds (and fractional seconds) â—Ź years and months (and quarters) convertible â—Ź (days and weeks convertible) â—Ź hours, minutes, and seconds convertible â—Ź No conversion between the three groups above!
- 4. Syntax No new syntaxis introduced. All handling of temporal values is done through functions: â—Ź datetime(...) â—Ź localdatetime(...) â—Ź date(...) â—Ź time(...) â—Ź localtime(...) â—Ź {datetime,localdatetime,date,time,localtime}.truncate(...) â—Ź {datetime,localdatetime,date,time,localtime}.{statement,transaction,realtime}(...) â—Ź duration(...) â—Ź duration.between(...), duration.inMonths(...), duration.inDays(...), duration.inSeconds(...)
- 5. Ways of creatingtemporal instants â—Ź Parsing from ISO 8601 string â—Ź Creating from components â—Ź Getting the current instant â—‹ using different clocks: statement, transaction, realtime (one of them being default) â—Ź Adding a Duration to an instant â—Ź Converting from other instants Ways of creating Duration â—Ź Parsing from ISO 8601 string â—Ź Creating from components â—Ź Compute difference between instants
- 6. Parsing Temporal Instantfrom ISO 8601 string ● datetime($string), localdatetime($string), date($string), time($string), localtime($string) ● date: YYYY-MM-DD, or YYYY-Www-D, or YYYY-Qq-DD, or YYYY-DDD (calendar date, week date, quarter date, ordinal date respectively) ○ dashes can be omitted, smaller units can be omitted ○ year with a sign prefix can be arbitrarily long, but then dashes may not be omitted ● time: HH:MM:SS.sss ○ colons can be omitted, smaller units can be omitted ● offset: ±HH:MM or Z ○ colons can be omitted, smaller units can be omitted ● zone: [name]
- 7. Parsing Temporal Instantfrom ISO 8601 string â—Ź datetime($string) â—‹ <date>T<time><offset><zone> â—‹ either offset, or zone, or both â—‹ smaller units may be omitted â—Ź localdatetime($string) â—‹ <date>T<time> â—‹ smaller units may be omitted â—Ź date($string) â—‹ <date> â—Ź time($string) â—‹ <time><offset> â—Ź localtime($string) â—‹ <time>
- 8. Creating Temporal Instantfrom components â—Ź datetime({...}), localdatetime({...}), date({...}), time({...}), localtime({...}) â—‹ Date based: â– year â– quarter â– month â– week â– weekYear â– day â– ordinalDay â– weekDay â—‹ Time based: â– hour â– minute â– second â– millisecond â– microsecond â– nanosecond â—‹ Other: â– timezone - the named timezone or offset if no name (supported by zoned types) â– offset - as a formatted offset string (supported by zoned types) â– offsetMinutes (supported by zoned types) â– epochMillis (only supported by DateTime) â– epochSeconds (only supported by DateTime) â– epochNanosOfSecond (only supported by DateTime)
- 9. Getting the currentTemporal Instant ● datetime(), localdatetime(), date(), time(), localtime() The above uses the (implementation specific) default clock, which is one of the below: Same point in time every invocation in the query: ● datetime.statement(), localtime.statement(), et.c... ● datetime.statement($timezone), et.c... Same point in time every invocation in the transaction: ● datetime.transaction(), localtime.transaction(), et.c... ● datetime.transaction($timezone), et.c… Actual time at invocation: ● datetime.realtime(), localtime.realtime(), et.c... ● datetime.realtime($timezone), et.c...
- 10. Converting Temporal Instantsbetween types â—Ź datetime({...}), localdatetime({...}), date({...}), time({...}), localtime({...}) â—Ź date - selects the date from a Date, or DateTime, or LocalDateTime â—Ź time - selects the time from a Time, LocalTime, DateTime, LocalDateTime â—Ź datetime - selects both the date and time from a DateTime or LocalDateTime Examples: â—Ź datetime({datetime:$aDateTimeOrLocalDateTime, timezone:"..."}) â—Ź datetime({date:$aDateOrDateTimeOrLocalDateTime, time:$anotherDateOrDateTimeOrLocalDateTime}) â—Ź datetime({datetime:...}), datetime({date:..., time:...}) datetime({datetime:..., timezone:...}), datetime({date:..., time:..., timezone:...}) â—Ź localdatetime({datetime:...}), localdatetime({date:..., time:...}) â—Ź time({time:...}), time({time:..., timezone:...}) â—Ź date({date:...}) â—Ź localtime({time:...})
- 11. Parsing Duration fromISO 8601 string â—Ź duration($string) â—Ź unit based format: PnYnQnMnWnDTnHnMnS â—‹ zero valued component can be omitted â—‹ T must precede time-based section (Hours and smaller) â—‹ Smallest component may be fractional â—‹ Examples: P15M, P1DT3H, PT48H, P1.5W â—Ź date-and-time based format: P<date>T<time> â—‹ smaller units may be omitted
- 12. Creating Duration fromComponents â—Ź duration({...}) â—‹ years â—‹ quarters â—‹ months â—‹ weeks â—‹ days â—‹ hours â—‹ minutes â—‹ seconds â—‹ milliseconds â—‹ microseconds â—‹ nanoseconds
- 13. Compute Duration asdifference between Instants Computing the duration from instant a to instant b: â—Ź duration.between(a, b) â—‹ uses natural units â—Ź duration.inSeconds(a, b) â—‹ uses hours, minutes, seconds â—Ź duration.inDays(a, b) â—‹ uses days â—Ź duration.inMonths(a, b) â—‹ uses months and years
- 14. Adding a Durationto a Temporal Instant Example: date("1984-10-11") + duration("P33Y5M3D") Note that this is not associative: â—Ź (date("2011-01-31") + duration("P1M")) + duration("P12M") â—‹ date({year:2012, month:2, day:28}) â—Ź date("2011-01-31") + (duration("P1M") + duration("P12M")) â—‹ date({year:2012, month:2, day:29})
- 15. Truncating a TemporalInstant datetime.truncate($unit, $instant) localdatetime.truncate($unit, $instant) date.truncate($unit, $instant) time.truncate($unit, $instant) localtime.truncate($unit, $instant) Supported units: â—Ź millennium â—Ź century â—Ź decade â—Ź year â—Ź weekYear - the first day of the first week of the week year of the specified instant (may be in december of previous year) â—Ź quarter â—Ź month â—Ź week â—Ź day â—Ź hour â—Ź minute â—Ź second â—Ź millisecond â—Ź microsecond
- 16. Comparing and ORDERBY â—Ź Temporal Instants comparable to other instants of same type â—Ź ORDER BY uses comparison order for Temporal Instants â—Ź ORDER BY groups by type when ordering by field with mixed types â—Ź Duration values are NOT comparable â—‹ because different months are of different lengths, and not all days are equally long â—Ź ORDER BY for Duration based on average length of days and months
- 17. Ordering durations -is the order consistent? ● PT672H = P28D ≤ P1M ≤ P31D = PT744H ; P1M ordered as: PT2629746S = PT730,485H (shortest possible: February) ● PT1416H = P59D ≤ P2M ≤ P62D = PT1488H ; P2M ordered as: PT5259492S = PT1460,970H (shortest possible two: Jan-Feb or Feb-Mar, longest possible two: Jul-Aug or Dec-Jan) ● PT2136H = P89D ≤ P3M ≤ P92D = PT2208H ; P3M ordered as: PT7889238S = PT2191,455H (shortest possible three: Feb-Apr, longest possible three: Nov-Jan or Jun-Aug or Jul-Sep) ● PT2880H = P120D ≤ P4M ≤ P123D = PT2952H ; P4M ordered as: PT10518984S = PT2921,940H (shortest possible four: Jan-Apr or Feb-May or Nov-Feb, longest possible four: May-Aug or Jul-Oct or Oct-Jan) ● PT3600H = P150D ≤ P5M ≤ P153D = PT3672H ; P5M ordered as: PT13148730S = PT3652,425H (shortest possible five: Feb-Jun, longest possible five: any range not including Feb) ● PT4344H = P181D ≤ P6M ≤ P184D = PT4416H ; P6M ordered as: PT15778476S = PT4382,910H (shortest possible six: Jan-Jun or Feb-Jul, longest possible six: Jul-Dec or Aug-Jan) ● PT5088H = P212D ≤ P7M ≤ P215D = PT5160H ; P7M ordered as: PT18408222S = PT5113,395H (shortest possible seven: any range including Feb, longest possible seven: Jul-Jan) ● PT5808H = P242D ≤ P8M ≤ P245D = PT5880H ; P8M ordered as: PT21037968S = PT5843,880H (shortest possible eight: Feb-Sep or Sep-Apr or Nov-Jun, longest possible eight: May-Dec or Jun-Jan) ● PT6552H = P273D ≤ P9M ≤ P276D = PT6624H ; P9M ordered as: PT23667714S = PT6574,365H (shortest possible nine: many, longest possible nine: May-Jan) ● PT7272H = P303D ≤ P10M ≤ P306D = PT7344H ; P10M ordered as: PT26297460S = PT7304,850H (shortest possible ten: Feb-Nov or Sep-Jun, longest possible ten: Mar-Dec or Apr-Jan) ● PT8016H = P334D ≤ P11M ≤ P337D = PT8088H ; P11M ordered as: PT28927206S = PT8035,335H (shortest possible eleven: many, longest possible eleven: Mar-Jan) ● PT8760H = P365D ≤ P12M = P1Y ≤ P366D = PT8784H ; P12M, P1Y ordered as: PT31556952S = PT8765,820H (longest possible: leap year) ● PT35040H = P1460D ≤ P4Y ≤ P1461D = PT35064H ; P4Y ordered as: PT126227808S = PT35063,280H (every 100 years, we skip a leap year) ● PT876576H = P36524D ≤ P100Y ≤ P36525D = PT876600H ; P100Y ordered as: PT3155695200S = PT876582,000H (every 400 years, we skip skipping the leap year) ● PT3506328H = P400Y = P146097D = PT3506328H ; P400Y ordered as: PT12622780800S = PT3506328,000H (this it the shortest number of months where we know exactly how many days it is)