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Datetime ​

The runtime injects a deterministic datetime module and the now environment variable.

Available Types ​

python
datetime.datetime(...)
datetime.timedelta(...)
datetime.DAYS
datetime.HOURS
datetime.MINUTES

Example ​

python
unlock_at = Variable()

@construct
def seed():
    unlock_at.set(now + datetime.DAYS * 7)

@export
def withdraw():
    assert now >= unlock_at.get(), "Too early"

Policy Examples ​

The meaning of now stays the same across all networks. What changes is whether chain time advances while the network is idle.

On an on_demand network:

  • no idle blocks are produced
  • now does not move until another block is created

On a periodic network with 10s empty blocks:

  • chain time advances roughly every 10 seconds
  • deadlines can expire even if no user transactions are submitted

That means contracts should treat time as a condition checked during execution, not as a background scheduler.

Notes ​

  • now comes from block context, not local wall-clock time
  • now is the finalized consensus block timestamp
  • every transaction in the same block sees the same now
  • the exposed Datetime and Timedelta types are restricted runtime wrappers
  • these types are also valid for exported-function annotations