Directors' Discretionary (DD) time proposals are discussed in this article, including the circumstances under which they are used and how to submit them. More information about past and present opportunities is available at JWST Director's Discretionary Time.

Overview of DD programs

Time-Critical DD 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 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 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.

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

• Small-scale pilot or test observations;
• 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 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.

Discovery DD proposals that are submitted not long after standard cycle proposal deadlines must have indisputable evidence for why they could not have been submitted during the standard cycle; otherwise, they will be disqualified. If such proposals are determined to be valid Discovery DDs, then the proposals might be evaluated by members of the standard TAC. They are also subject to longer periods of external peer review.

Joint DD 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

• Rejected GO and DD 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. 
• Targets of Opportunity (ToO) are not allowed for Director's Discretionary Proposals. This includes requests to reserve ToO targets that have not yet been discovered.

• Pure Parallel and Survey programs may not be submitted as DD proposals. These programs are suited to large pools of targets where the science goals can be achieved regardless of the exact number of targets observed and the specific targets observed and are, thus, incompatible with the scope and purpose of the DD opportunity.

• Preparation for future observing cycles is typically insufficient justification for Director's Discretionary time.
• 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 Cycle 4 JWST Call for Proposals. 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.

Subject to availability of funds from NASA, STScI will provide financial support for U.S. PIs and Co-Is of approved DD programs. See the JWST Grant Funding and Budget Submissions page.

Scheduling requirements and execution timeline

All DD proposals undergo extensive review before they are potentially executed, including external peer review and internal instrument review. When considering scheduling feasibility of the requested observations, proposal PIs must factor in time to complete each component of the review, as they impact the timeline for implementation. More details on the review timeline are given below; refer also to the JWST Observation Review and Implementation page.

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.

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; Discovery DDs may take longer (as by definition they are not time-critical).

NIRSpec MOS programs must be finalized at least 8 weeks before execution. Consequently, NIRSpec MOS is not available for disruptive DD programs. The new NIRCam DHS mode is also not available for disruptive DD programs.

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.

DD proposal submissions

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 Cycle 4 JWST Anonymous Proposal Reviews, except the review of the team expertise will be done internally by the Science Policy Division. 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 and to select the DD type from the drop-down menu. 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 JWST Proposing article. You will be providing all necessary information (including all necessary observing parameters) via 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. 

Proposal template and page limits

Templates for the PDF attachment can be found on the Cycle 4 JWST Preparation of the PDF Attachment page. Make sure to use the template appropriate for DD proposals. The PDF attachment should follow the page limits for proposals of the same-sized GO proposal category, as shown on the Cycle 4 JWST Guidelines and Checklist for Proposal Preparation page.

Proposal review

Upon completion of your DD submission, your program will be transferred to the STScI Science Policy Division for processing by our DD team.

The DD team will first determine whether the proposal complies with DD policies, including checking for DD justifications and timing requirements, and ensuring there are no Dual Anonymous Peer Review or page limit violations. Re-submissions of previously-rejected proposals will be rejected automatically.

Next the DD team will undertake an initial review of the proposal against the primary DD criteria and will perform a scientific urgency assessment. Proposals that do not meet those criteria or are deemed not scientifically urgent will not be distributed for further review; the Principal Investigator will be informed of that decision, and is free to submit the proposal at the next standard cycle deadline.

DD proposals passing these initial reviews are sent out for scientific review by members of the community. Ideally, each proposal will receive four reviews; we will proceed with fewer reviews in exceptionally time-sensitive cases where reviewers are non-responsive or challenging to recruit. The DD evaluation rubric is provided below.

Help and more information

If you run into problems submitting a DD request, contact the STScI JWST Help Desk for investigation and resolution.

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

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:

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.