The question: how do I check if a field is blank?

You want a formula that uses a value when it exists and falls back when it does not. The cleanest pattern in Airtable is to test the field directly for the non‑blank case.

Key patterns

Check not blank

IF({Field Name}, "value if present", "value if blank")

Check blank (explicit)

IF(NOT({Field Name}), "value if blank", "value if present")

Tip: testing {Field Name} directly is the simplest way to detect “has something”.

Practical example: imported vs created time

Goal: show an imported timestamp when available, otherwise show your fallback field.

IF({Original Time Stamp}, {Original Time Stamp}, {Time Stamp})

Notes:

Field references are not quoted. Quoting turns them into literal strings.
If you truly want a literal string as the fallback, wrap only the fallback in quotes.

IF({Original Time Stamp}, {Original Time Stamp}, "No timestamp")

Formatting dates cleanly

If you mix raw date values with already formatted text, your output will be inconsistent. Format the date part explicitly with DATETIME_FORMAT.

IF(
  {Original Time Stamp},
  DATETIME_FORMAT({Original Time Stamp}, "M/DD/YYYY h:mm A"),
  DATETIME_FORMAT({Time Stamp}, "M/DD/YYYY h:mm A")
)

Alternative: if {Time Stamp} is not a date, format only the original and keep the fallback as text.

IF(
  {Original Time Stamp},
  DATETIME_FORMAT({Original Time Stamp}, "M/DD/YYYY h:mm A"),
  {Time Stamp}
)

Quick reference

Goal	Formula
Non‑blank first, fallback if blank	`IF({Field}, {Field}, {Fallback})`
Explicit blank check	`IF(NOT({Field}), {Fallback}, {Field})`
Format a date when present	`IF({Date}, DATETIME_FORMAT({Date}, "M/DD/YYYY h:mm A"), "n/a")`

Common pitfalls

Quoting field names: {Field} is correct, "{Field}" is literal text
Mixing raw dates with formatted strings in the same output
Forgetting to format the date after using SET_TIMEZONE

Airtable IF Blank vs Not Blank: Simple Patterns That Work