ligo/gitlab-pages/docs/advanced/timestamps-addresses.md

id	title
timestamps-addresses	Timestamps, Addresses

Timestamps

LIGO features timestamps, as Michelson does, while bakers baking the block (including the transaction in a block) are responsible for providing the given current timestamp for the contract.

Current Time

You can obtain the current time using the built-in syntax specific expression, please be aware that it is up to the baker to set the current timestamp value.

const today : timestamp = now

let today : timestamp = Current.time

let today : timestamp = Current.time;

When running code with ligo CLI, the option --predecessor-timestamp allows you to control what now returns.

Timestamp Arithmetic

In LIGO, timestamps can be added to integers, allowing you to set time constraints on your smart contracts. Consider the following scenarios.

In 24 hours

const today : timestamp = now
const one_day : int = 86400
const in_24_hrs : timestamp = today + one_day
const some_date : timestamp = ("2000-01-01T10:10:10Z" : timestamp)
const one_day_later : timestamp = some_date + one_day

let today : timestamp = Current.time
let one_day : int = 86400
let in_24_hrs : timestamp = today + one_day
let some_date : timestamp = ("2000-01-01t10:10:10Z" : timestamp)
let one_day_later : timestamp = some_date + one_day

let today : timestamp = Current.time;
let one_day : int = 86400;
let in_24_hrs : timestamp = today + one_day;
let some_date : timestamp = ("2000-01-01t10:10:10Z" : timestamp);
let one_day_later : timestamp = some_date + one_day;

24 hours Ago

const today : timestamp = now
const one_day : int = 86400
const in_24_hrs : timestamp = today - one_day

let today : timestamp = Current.time
let one_day : int = 86400
let in_24_hrs : timestamp = today - one_day

let today : timestamp = Current.time;
let one_day : int = 86400;
let in_24_hrs : timestamp = today - one_day;

Comparing Timestamps

You can also compare timestamps using the same comparison operators as for numbers.

const not_tommorow : bool = (now = in_24_hrs)

let not_tomorrow : bool = (Current.time = in_24_hrs)

let not_tomorrow : bool = (Current.time == in_24_hrs);

Addresses

The type address in LIGO is used to denote Tezos addresses (tz1, tz2, tz3, KT1, ...). Currently, addresses are created by casting a string to the type address. Beware of failures if the address is invalid. Consider the following examples.

const my_account : address =
  ("tz1KqTpEZ7Yob7QbPE4Hy4Wo8fHG8LhKxZSx" : address)

let my_account : address =
  ("tz1KqTpEZ7Yob7QbPE4Hy4Wo8fHG8LhKxZSx" : address)

let my_account : address =
  ("tz1KqTpEZ7Yob7QbPE4Hy4Wo8fHG8LhKxZSx" : address);

Signatures

The type signature in LIGO datatype is used for Tezos signature (edsig, spsig). Signatures are created by casting a string. Beware of failure if the signature is invalid.

Here is how you can define a signature:

const my_sig : signature =
  ("edsigthTzJ8X7MPmNeEwybRAvdxS1pupqcM5Mk4uCuyZAe7uEk68YpuGDeViW8wSXMrCi5CwoNgqs8V2w8ayB5dMJzrYCHhD8C7" :
  signature)

let my_sig : signature =
   ("edsigthTzJ8X7MPmNeEwybRAvdxS1pupqcM5Mk4uCuyZAe7uEk68YpuGDeViW8wSXMrCi5CwoNgqs8V2w8ayB5dMJzrYCHhD8C7" :
   signature)

let my_sig : signature =
("edsigthTzJ8X7MPmNeEwybRAvdxS1pupqcM5Mk4uCuyZAe7uEk68YpuGDeViW8wSXMrCi5CwoNgqs8V2w8ayB5dMJzrYCHhD8C7" :
signature);

Keys

The type key in LIGO is used for Tezos public keys. Do not confuse them with map keys. Keys are made by casting strings. Beware of failure if the key is invalid.

Here is how you can define a key.

const my_key : key =
("edpkuBknW28nW72KG6RoHtYW7p12T6GKc7nAbwYX5m8Wd9sDVC9yav" : key)

let my_key : key =
  ("edpkuBknW28nW72KG6RoHtYW7p12T6GKc7nAbwYX5m8Wd9sDVC9yav" : key)

let my_key : key =
  ("edpkuBknW28nW72KG6RoHtYW7p12T6GKc7nAbwYX5m8Wd9sDVC9yav" : key);