Temporal types

Temporal types can be stored as properties of a vertex or edge. The user can use Cypher queries or procedures to read or write these properties. The following table summarizes the temporal types that Memgraph currently supports:

name	description
Duration	Data type that represents a period of time.
Date	Data type that represents a date with year, month, and day.
LocalTime	Data type that represents time within a day without timezone.
LocalDateTime	Data type that represents a date and local time.

note

All types excluding Duration are ISO 8601 compliant.

Duration

You can create Duration from a string or a map by calling the function duration.

For strings, the duration format is: P[nD]T[nH][nM][nS] where n stands for number, and the capital letters are used as a separator with each field in [] marked optional. For strings, Memgraph only allows the last field to be a double, e.g., P2DT2.5H. However, for maps, every field can be a double, an int or a mixture of both. We also support negative durations.

name	description
D	Days
H	Hours
M	Minutes
S	Seconds

Example:

CREATE (:F1Laps {lap : duration("PT2M2.33S")})

Maps can contain the following six fields: day, hour, minute, second , millisecond and microsecond.

Example:

CREATE (:F1Laps {lap : duration({minute:2, seconds:2, microseconds:33})})

At this point, it must be pointed out that durations internally hold microseconds. Each of the fields specified above is first converted to microseconds and then reduced by addition to a single value. This has an interesting use case:

CREATE (:F1Laps {lap : duration({minute:2, seconds:-2, microseconds:-33})})

This converts minutes, seconds to microseconds and effectively produces the following equation: minutes - seconds - microseconds.

Each of the individual fields of a duration can be accessed through its properties as follows:

name	description
day	This converts all the microseconds to days and returns them.
hour	This subtracts days and returns the leftover as hours.
minute	This subtracts the days and returns the leftover as minutes.
second	This subtracts the days and returns the leftover as seconds.
millisecond	This subtracts the days and returns the leftover as milliseconds.
microsecond	This subtracts the days and returns the leftover as microseconds.
nanosecond	This subtracts the days and returns the leftover as nanoseconds.

Example:

MATCH (f:F1Laps) RETURN f.lap.minute

Date

You can create Date from a string or map by calling the function Date. For strings, the date format is specified by the ISO 8601: YYYY-MM-DD or YYYYMMDD or YYYY-MM.

name	description
Y	Year
M	Month
D	Day

The smallest year is 0 and the highest is 9999.

You can call date without arguments. This effectively sets the date field to the current date of the calendar (UTC clock).

Example:

CREATE (:Person {birthday : date("1947-07-30")})

For maps, three fields are available: year, month, day.

Example:

CREATE (:Person {birthday: date({year:1947, month:7, day:30})})

You can access the individual fields of a date through its properties:

name	description
year	Returns the year field
month	Returns the month field
day	Returns the day field

Example:

MATCH (b:Person) RETURN b.birthday.year

LocalTime

You can create LocalTime from a string or map by calling the function localtime. For strings, the local time format is specified by the ISO 8601: [T]hh:mm:ss or [T]hh:mm or [T]hhmmss or [T]hhmm or [T]hh.

name	description
h	hours
m	minutes
s	seconds

seconds can be defined as decimal fractions with up to 6 digits. The first 3 digits represent milliseconds, and the last 3 digits microseconds. For example, the string T22:10:32.300600 specifies 300 milliseconds and 600 microseconds.

You can call localtime without arguments. This effectively sets the time field to the current time of the calendar (UTC clock).

Example:

CREATE (:School {Calculus : LocalTime("09:15:00")})

For maps, there are 5 fields available: hour, minute, second, millisecond and microsecond.

Example:

CREATE (:School {Calculus : LocalTime({hour:9, minute:15})})

You can access the individual fields of a LocalTime through its properties:

name	description
hour	Returns the hour field
minute	Returns the minute field
second	Returns the second field
millisecond	Returns the millisecond field
microsecond	Returns the microsecond field

Example:

MATCH (s:School) RETURN s.Calculus.hour

LocalDateTime

You can create LocalDateTime from a string or map by calling the function localdatetime. For strings, the local time format is specified by the ISO 8601: YYYY-MM-DDThh:mm:ss or YYYY-MM-DDThh:mm or YYYYMMDDThhmmss or YYYYMMDDThhmm or YYYYMMDDThh.

name	description
Y	Year
M	Month
D	Day
h	Hours
m	Minutes
s	Seconds

You can call localdatetime without arguments. This effectively sets the date and time fields to the current date and time of the calendar (UTC clock). Example:

CREATE (:Flights {AIR123 : LocalDateTime("2021-10-05T14:15:00")})

For maps the following fields are available: year, month, day, hour, minute, second, millisecond and microsecond.

Example:

CREATE (:Flights {AIR123 : LocalDateTime(year:2021, month:10, day:5, hour:14, minute:15)})

You can access the individual fields of LocalDateTime through its properties:

name	description
year	Returns the year field
month	Returns the month field
day	Returns the day field
hour	Returns the hour field
minute	Returns the minute field
second	Returns the second field
millisecond	Returns the millisecond field
microsecond	Returns the microsecond field

Example:

MATCH (f:Flights) RETURN f.AIR123.year

Temporal types arithmetic

Temporal types support native arithmetic, and the operations are summarized in the following table:

Duration operations:

op	result
duration + duration	duration
duration - duration	duration
-duration	duration

Date operations:

op	result
date + duration	date
duration + date	date
date - duration	date
date - date	duration

LocalTime operations:

op	result
localtime + duration	localtime
duration + localtime	localtime
localtime - duration	localtime
localtime - localtime	duration

LocalDateTime operations:

operation	result
localdatetime + duration	localdatetime
duration + localdatetime	localdatetime
localdatetime - duration	localdatetime
localdatetime - localdatetime	duration

Procedures API

Temporal types can also be used within query modules. Check out the documentation for the Pyhon API and C API.