Directors' Discretionary (DD) time proposals are discussed in this article, including the circumstances under which they are used and how to submit them.

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Types of DD time proposals

Time-critical DD time proposals

Time-Critical Director's Discretionary time proposals are suitable for observations that could not have been requested in a previous observing cycle and cannot wait for the next standard observing cycle. Examples of potentially appropriate Time-Critical DD time requests include:

Follow-up of newly-discovered unexpected transient phenomena;
When developments since the last proposal cycle make a time-critical observation necessary.

Examples of observations that are not suitable for Time-Critical DD time requests include:

Observations that could plausibly have been proposed in the most recent regular proposal cycle, possibly as a target of opportunity proposal;
Observations that were proposed in a recent regular proposal cycle, and were rejected;
Observations that could wait until the next proposal cycle with no significant reduction in the expected scientific return.

Time-Critical DD time proposals should be small, typically <15 hours in size. Proposals requesting significantly more than 15 hours are generally better suited for the standard observing cycle and its TAC review process.

Discovery DD time proposals

Discovery Director's Discretionary Time proposals are suitable for observations of compelling scientific urgency that significantly accelerate scientific discovery. Examples of potentially appropriate Discovery DD time requests include:

The timely follow-up of new discoveries that provide a critical link in the understanding of phenomena that would have significant impact on the broader field;
Small-scale pilot or test observations that would have an extraordinary impact on the broader field if they were successful.

Examples of observations that are not suitable for Discovery DD time requests include:

Observations that are a subset of larger observing programs planned for future cycles;
Observations that are requested in order to prepare for more/follow-up observations in future cycles;
Observations that were proposed in a recent regular proposal cycle, and were rejected, and for which the available information and/or observations have not substantially changed;
Observations that do not have significantly compelling scientific urgency, and would therefore be more appropriately evaluated by the TAC review process during a standard observing cycle.

Discovery DD time proposals should be small, typically <10 hours in size. Unless the science is highly compelling, proposals requesting significantly more than 10 hours are generally better suited for the standard observing cycle and its TAC review process.

Joint DD time and Target of Opportunity proposals

Requests to reserve target of opportunity targets that have not yet been discovered are not appropriate for Director's Discretionary Proposals.

Joint JWST-HST DD proposals are permitted. All joint JWST-HST proposals should be submitted using the JWST APT. Joint DD proposals with other facilities are not permitted.

General DD proposal requirements

Please note: All scheduling requirements must be specified, including timing requirements that would require disruptive (< 14 days) or ultra-disruptive (< 3 days) turnaround times for activation. The limitations on each of these are described in JWST Target of Opportunity Observations. The activation timescale begins when the notification of acceptance is sent to the PI. Most proposals will be subject to external peer review after they are submitted; when considering whether a proposal is disruptive or non-disruptive, PIs should factor in a minimum of 5 days for an expedited review process to complete, and 5-7 days for proposals submitted late in the week. The typical turnaround time for proposal reviews is ~3 weeks.

NIRSpec MOS programs must be finalized at least 4 weeks before execution. Consequently, NIRSpec MOS is not available for disruptive (< 14 day) DD programs.

Rejected GO proposals may not be re-submitted as DD proposals unless there has been a substantive change in the basis for the proposal, e.g. new observations or theoretical advances.

The Special Requirements section must include an explicit statement on when the observations have to be executed.

Proposals that imply a time requirement, e.g., “as soon as possible,” but do not specify a disruptive or ultra-disruptive activation time, will be returned. There are a limited number of ultra-disruptive activations available in this cycle, so please justify accordingly.

Once a proposal is approved, any subsequent requests for changes may jeopardize the execution of the program and will be accepted only under highly exceptional circumstances.

The use of Director's Discretionary time, as opposed to time awarded during the regular observing cycle by the standard TAC review process, MUST be well justified. In particular, preparation for future observing cycles is typically insufficient justification for Director's Discretionary time.

Subject to availability of funds from NASA, STScI will provide financial support for U.S. PIs and Co-Is of approved DD programs.

More information about past and present opportunities is available at JWST Director's Discretionary time.

DD proposal rubric

All DD time proposals will be evaluated through external peer review according to the following guiding rubric points:

The scientific merit of the proposed investigation and its potential contribution to the advancement of scientific knowledge;
The program’s importance to astronomy in general;
The scientific urgency of the observations and the necessity of JWST to achieve the program's science goals;
Whether the science is comparable in quality to approved programs from the standard TAC process;
The justification of the resource request;
Additionally for Time-Critical DDs: Why these observations could not have been proposed in a previous cycle, and cannot wait for the next cycle;
Additionally for Discovery DDs: Whether these observations have the potential to significantly accelerate major scientific discovery.

The rubric grades are broken down numerically as follows:

Criterion	Grade of 1 (Highest Grade)	Grade of 3	Grade of 5 (Lowest Grade)
General scientific merit and the potential to advance scientific knowledge	The scientific goals of the DD are clear, and the proposed observations will clearly achieve those goals. The observations will have transformative impact on the astronomical sub-field.	The scientific goals of the DD are moderately clear, and/or the proposed observations will achieve a subset of those goals. The observations will have moderate impact on the astronomical sub-field.	The scientific goals of the DD are generally unclear, and it is not clear how the proposed observations will achieve those goals. The observations will have limited or no potential to impact the astronomical sub-field.
Importance to broader astronomy	The proposed observations will have transformative impact on other sub-fields or broader fields of astronomy.	The proposed observations will have moderate impact on other sub-fields or broader fields of astronomy.	The proposed observations will have limited or no potential to impact other sub-fields or broader fields of astronomy.
For Time-Critical DD time proposals: The scientific urgency, i.e., the timeliness of the proposed observations as a DD.	The proposed observations could not have been proposed in a previous observing cycle, and the observations cannot wait for a future proposing cycle without significant reduction in scientific return.	It is not clear that the proposed observations could not have been proposed in a previous observing cycle, and/or they could wait for a future observing cycle with some moderate reduction in scientific return.	The proposed observations could have been proposed in a previous cycle, and/or could wait for a future cycle without significant reduction in scientific return.
For Discovery DD time proposals: The potential for this time investment to significantly accelerate major scientific discovery.	The proposed observations are novel, and would substantially alter the paradigm and/or advance new science in the field.	The proposed observations are somewhat novel, and would moderately alter the paradigm and/or advance new science in the field.	The proposed observations are not novel, and have limited or no potential to substantially alter the paradigm and/or advance new science in the field.

DD time proposals are additionally evaluated on a binary (true/false) scale in regards to whether or not the following statements are true:

JWST observations are necessary to achieve the program's science goals;
The science is comparable in quality to approved programs from the standard TAC process;
The resource request is justified.

DD proposal preparation

DD proposals must be submitted in, and will be reviewed in, an anonymous format. The review process is similar to that used in the JWST Cycle 3 Anonymous Proposal Reviews, except the review of the team expertise will be done internally by the Science Policies Group. Please fill out the "Team Expertise and Background" section of the proposal, but it will not be shared with the reviewers.

Proposers should use the Astronomer's Proposal Tool (APT) to submit their DD programs and make sure to check the DD checkbox. To download and install APT, go to the APT webpage. For help on using APT to prepare and submit a JWST program, please refer to the Getting Started with Planning JWST Observations article. You will be providing all necessary information (including all necessary observing parameters) via the APT tool and you will attach your scientific justification and observation description as a PDF attachment to your submission, as is typical for JWST GO proposals. More detailed information is included below.

Templates for the PDF attachment of the "Scientific Justification" can be found on the current cycle's preparation of the PDF attachment article. Page limitations should follow the Page Limits for the PDF Attachment for proposals of the same-sized proposal category, as shown on the JWST Guidelines and Checklist for Proposal Preparation - Cycle 3 page. Make sure to use the template appropriate for DD proposals. And make sure you follow Cycle 3 guidelines instead of Cycle 4 (the page will say the information is dated, but that warning is there for Cycle 4 proposers).

Upon completion of your DD submission, your program will be transferred to the STScI for processing by our DD team. If you run into problems submitting a DD request, contact the JWST Helpdesk for investigation and resolution.

Please refer to JWST Director's Discretionary Time for more information regarding DD proposals.

Proposals for DD time must be sufficiently detailed for adequate evaluation. The required level of detail is the same as that required for proposals submitted for the regular observing cycles, as described in the current James Webb Space Telescope Call for Proposals for Cycle 3.

Among other things:

both the proposed observations and the use of DD time must be explicitly justified;
there must be an adequate description of how the proposed observations relate to the current state of knowledge;
the proposed observations must be described in sufficient detail to allow technical evaluation;
the APT file must be telescope-ready.

Notable updates	17 Sep 2024 Clarifications made for types of DDT proposals\| 20 Aug 2024 All joint JWST-HST proposals should be submitted using the JWST APT.
Originally published	01 Jul 2024

JWST User Documentation

Cycle 3 Director's Discretionary (DD) Time Proposals