session

Trading session detection and classification. The session namespace provides boolean flags for determining when the current bar falls within different trading session phases or session boundaries (first/last bar of the day). Use these flags to trigger actions at specific times during the trading day.

Quick Example 

from pynecore.lib import close, session, bar_index, label, strategy

@script.indicator(title="Session Detector", overlay=True)
def main():
    # Mark the first bar of each day's session
    if session.isfirstbar_regular:
        label.new(bar_index, close, "Day start", textcolor="color.green")
    
    # Mark the last bar of regular trading hours
    if session.islastbar_regular:
        label.new(bar_index, close, "Regular close", textcolor="color.red")
    
    # Trade only during market hours
    if session.ismarket:
        strategy.entry("Long", strategy.long)

Variables

All session variables are read-only module properties (accessed without parentheses).

isfirstbar_regular

Returns True if the current bar is the first bar of the day’s regular trading session, False otherwise.

Type: bool

Example:

is_first: bool = session.isfirstbar_regular  # True on first regular bar of day

isfirstbar

Returns True if the current bar is the first bar of the trading day, False otherwise. On bars of the extended hours (syminfo.session == session.extended) only the first bar of the pre-market is the first bar.

Type: bool

Example:

is_session_start: bool = session.isfirstbar  # True at session open

islastbar_regular

Returns True if the current bar is the last bar of the day’s regular trading session, False otherwise.

Type: bool

Example:

is_last: bool = session.islastbar_regular  # True on last regular bar of day

islastbar

Returns True if the current bar is the last bar of the trading day, False otherwise. On bars of the extended hours only the last bar of the post-market is the last bar.

Type: bool

Example:

is_session_end: bool = session.islastbar  # True at session close

ismarket

Returns True if the current bar is within regular market hours, False otherwise. Every bar of a regular-hours chart is; on bars of the extended hours the bar has to open inside the regular hours.

Type: bool

Example:

trading_hours: bool = session.ismarket  # True during market hours

ispremarket

Returns True if the current bar is within pre-market hours, False otherwise: a bar of the extended hours opening before the day’s regular open. Always False on a regular-hours chart.

Type: bool

Example:

early_hours: bool = session.ispremarket  # True on the 04:00-09:00 bars of a US stock

ispostmarket

Returns True if the current bar is within post-market hours, False otherwise: a bar of the extended hours opening at or after the day’s regular close (13:00 on an early-close day). Always False on a regular-hours chart.

Type: bool

Example:

after_hours: bool = session.ispostmarket  # True on the 16:00-19:00 bars of a US stock

Constants

NameTypeDescription
session.regularSessionSession type for regular trading hours only (no extended hours).
session.extendedSessionSession type including extended hours (pre-market and post-market).

Compatibility Notes

  • Extended hours: the properties follow the symbol’s extended_hours template and the session flag of its TOML (see Extended Trading Hours). The bars of an extended-hours chart are cut from the extended open, so the regular open never falls on a bar edge: the regular hours are read by the bar’s open (the first regular bar of a 60-minute US stock chart is the 10:00 bar, not the 09:00 bar that contains 09:30), while the chart’s own open and close are the bars that contain them. Measured on the NASDAQ:AAPL 60-minute chart on both hours.
  • Daily+ charts: On daily or longer timeframes, session variables still evaluate using normal session overlap logic. Results depend on whether the bar’s time range overlaps with configured session hours. This may differ from TradingView, which returns False for all session variables on daily+ charts.